Search

Oncocytic (Hürthle cell) carcinoma of the thyroid (HCC) is genetically characterized by complex I mitochondrial DNA mutations and widespread chromosomal losses. Here, we utilize RNA sequencing and metabolomics to identify candidate molecular effectors activated by these genetic drivers. We find glutathione biosynthesis, amino acid metabolism, mitochondrial unfolded protein response, and lipid peroxide scavenging to be increased in HCC. A CRISPR-Cas9 knockout screen in a new HCC model reveals which pathways are key for fitness, and highlights loss of GPX4, a defense against lipid peroxides and ferroptosis, as a strong liability. Rescuing complex I redox activity with the yeast NADH dehydrogenase (NDI1) in HCC cells diminishes ferroptosis sensitivity, while inhibiting complex I in normal thyroid cells augments ferroptosis induction. Our work demonstrates unmitigated lipid peroxide stress to be an HCC vulnerability that is mechanistically coupled to the genetic loss of mitochondrial complex I activity., Significance: HCC harbors abundant mitochondria, mitochondrial DNA mutations, and chromosomal losses. Using a CRISPR-Cas9 screen inspired by transcriptomic and metabolomic profiling, we identify molecular effectors essential for cell fitness. We uncover lipid peroxide stress as a vulnerability coupled to mitochondrial complex I loss in HCC. See related article by Frank et al., p. 1884. This article is highlighted in the In This Issue feature, p. 1749., (©2023 The Authors; Published by the American Association for Cancer Research.)

Hürthle cell carcinoma (HCC) is a rare type of thyroid cancer with high rates of distant metastasis and recurrence. Along with the scarcity of effective systemic therapies for HCC, these factors contribute to poor clinical outcomes. The immunologic features of HCC are poorly defined and response rates with immune checkpoint blockade have not been reported. A more comprehensive understanding of the immune landscape and factors that predict response to checkpoint inhibitors is needed. We performed RNA sequencing on 40 tumors to characterize the neoantigen landscape and immune microenvironment of HCC. We analyzed transcriptomic profiles, tumor-infiltrating immune cell populations, and measures of T-cell activation/dysfunction and correlated these to genetic features such as tumor mutation burden, neoantigen burden, mitochondrial mutations, and LOH from chromosomal uniparental disomy. Finally, immune profiles of patients with recurrence were compared with those of patients without recurrence. HCC tumors exhibited low levels of immune infiltration, with the more aggressive widely invasive phenotype associated with more immune depletion. There was a negative correlation between tumor mutation burden, neoantigen burden, programmed cell death ligand 1 (PD-L1) expression, and the immune infiltration score. HCC tumors that exhibited a global LOH from chromosomal uniparental disomy or haploidization had the lowest level of immune infiltration. HCC tumors that recurred displayed an immune-depleted microenvironment associated with global LOH and aerobic glycolysis. These findings offer new insights into the functional immune landscapes and immune microenvironment of HCC. Our data identify potential immunologic vulnerabilities for these understudied and often fatal cancers., Significance: The immune landscape of HCC is poorly defined and response rates to immunotherapy have not been reported. The authors found the immune microenvironment in HCC to be depleted. This immunosuppression is associated with a global LOH from haploidization and uniparental disomy, resulting in whole chromosome losses across the genome., (© 2023 The Authors; Published by the American Association for Cancer Research.)

Concentric calcifications, also known as psammoma bodies, are a relatively frequent finding in certain types of tumors, particularly papillary thyroid carcinoma (PTC). In the thyroid, they have been assigned a significant role in the diagnosis of PTC and in distinguishing between these tumors and other types of thyroid neoplasms. Concentric calcifications have also less commonly been noted in other processes in the thyroid, such as in tumors characterized by cells containing abundant oxyphilic cytoplasm (i.e., Hürthle cells). We have studied 12 patients with oncocytic thyroid follicular tumors that contained scattered psammomatous calcifications that led to difficulties in diagnosis. The patients were 9 women and 3 men, aged 34 to 63 years. 10 cases corresponded to benign, non-invasive oncocytic tumors and 2 cases were minimally invasive follicular carcinomas of oncocytic (so called Hürthle cell) type. The psammomatous calcifications were randomly scattered throughout the lesions and were present as a focal, incidental finding in 8 cases and were diffuse in 4 cases. They were composed of concentrically laminated deposits of dense basophilic material closely resembling psammoma bodies, often associated with more homogeneous deposits of lightly eosinophilic material without concentric lamination that were interpreted as precipitated thyroglobulin. Seven patients with clinical follow-up, including one with minimally invasive carcinoma, were alive and well between 5 and 12 years after diagnosis. Concentric laminated calcifications may be encountered in oncocytic (Hürthle cell) follicular tumors and should not be interpreted as indicative of PTC in the context of oncocytic neoplasms of the thyroid., Competing Interests: Declaration of competing interest David Suster receives royalty payments for text book authorship from Elsevier. Natali Ronen has no disclosures to report., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The combination of various therapeutic modalities has received considerable attention for improving antitumor performance. Herein, an innovative nanohybrid, namely CaO 2 @FePt-DOX@PDA@CM (CFDPM), was developed for synergistic chemotherapy/chemodynamic therapy/Ca 2+ overloading-mediated amplification of tumor oxidative stress and photothermal enhanced cancer therapy. Camouflage of the 4T1 cell membrane enabled CFDPM to escape the immune surveillance and accumulate in the tumor tissue. Ca 2+ , released from CaO 2 , could lead to mitochondrial dysfunction and facilitate the production of reactive oxygen species to amplify intracellular oxidative stress. Meanwhile, the increase of H 2 O 2 concentration could enhance the efficiency of the chemodynamic therapy (CDT). Moreover, the hypoxic condition could be alleviated remarkably, which is attributed to the sufficient O 2 supply by CaO 2 , resulting in the suppression of drug resistance and promotion of the chemotherapeutic effect. The nanohybrids involving Ca 2+ overloading/CDT/chemotherapy could synergistically amplify the tumor oxidative stresses and remarkably aggravate the death of cancer cells. Significantly, the excellent photothermal conversion performance of CFDPM could further promote the tumoricidal effect. The in vitro and in vivo studies revealed that CFDPM could effectively advance the therapeutic efficiency via the cooperation of various therapeutic modalities to optimize their individual virtue, which would open a valuable avenue for effective cancer treatment.

Chief cells are the predominant cells in parathyroid glands of healthy adults; however, parathyroid oxyphil cells, whose function is unknown, increase dramatically in patients with secondary hyperparathyroidism (SHPT). Calcitriol and calcimimetics are the most powerful treatments for SHPT, while the mechanisms leading to calcitriol or calcimimetic resistance in oxyphil cell-predominant SHPT are unknown. Here we used transcriptomic and proteomic techniques to characterize oxyphil cells by comparing the differences between chief and oxyphil cell nodules of parathyroid glands in uremic patients. Compared to chief cell nodules, the most marked expression increases in oxyphil cell nodules were for mitochondrion-associated proteins. The mitochondria number and mitochondrial DNA content were also significantly increased in oxyphil cell nodules. Moreover, oxyphil cell nodules expressed parathyroid-specific factors, and exhibited lower levels of proliferation-related proteins but higher synthesis and secretion level of parathyroid hormone (PTH). The protein expression of SHPT-regulating factors, including vitamin-D receptor, calcium-sensing receptor and Klotho, were significantly downregulated in oxyphil cell nodules. Therefore, oxyphil cells characterized by enrich mitochondria in uremic patients showed higher synthesis and secretion of PTH but lower expression of SHPT regulators than chief cells, which may contribute to the pathophysiology of SHPT and the treatment resistance to calcitriol and calcimimetics., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

So-called oncocytic papillary renal cell carcinoma (OPRCC) is a poorly defined variant of papillary renal cell carcinoma. Since its first description, several studies were published with conflicting results, and thus precise definition is lacking. A cohort of 39 PRCCs composed of oncocytic cells were analyzed. Cases were divided into 3 groups based on copy number variation (CNV) pattern. The first group consisted of 23 cases with CNV equal to renal oncocytoma. The second group consisted of 7 cases with polysomy of chromosomes 7 and 17 and the last group of 9 cases included those with variable CNV. Epidemiologic, morphologic and immunohistochemical features varied among the groups. There were not any particular histomorphologic features correlating with any of the genetic subgroups. Further, a combination of morphologic, immunohistochemical, and molecular-genetic features did not allow to precisely predict biologic behavior. Owing to variable CNV pattern in OPRCC, strict adherence to morphology and immunohistochemical profile is recommended, particularly in limited samples (i.e., core biopsy). Applying CNV pattern as a part of a diagnostic algorithm can be potentially misleading. OPRCC is a highly variable group of tumors, which might be misdiagnosed as renal oncocytoma. Using the term OPRCC as a distinct diagnostic entity is, thanks to its high heterogeneity, questionable., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Hürthle cell carcinoma (HCC) is a distinct type of thyroid cancer genetically characterized by DNA copy number alterations (CNA), typically of genome haploidization type (GH-type). However, whether CNA also occurs in benign Hürthle cell adenomas (HCA) or Hürthle cell hyperplastic nodules (HCHN), and have diagnostic impact in fine-needle aspiration (FNA) samples, remains unknown. To address these questions, we (1) analyzed 26 HCC, 24 HCA, and 8 HCHN tissues for CNA and other mutations using ThyroSeq v3 (TSv3) next-generation sequencing panel, and (2) determined cancer rate in 111 FNA samples with CNA and known surgical outcome. We identified CNA, more often of the GH-type, in 81% of HCC and in 38% HCA, but not in HCHN. Among four HCC with distant metastasis, all had CNA and three TERT mutations. Overall, positive TSv3 results were obtained in 24 (92%) HCC, including all with ATA high risk of recurrence or metastasis. Among 111 FNA cases with CNA, 38 (34%) were malignant and 73 (66%) benign. A significant correlation between cancer rate and nodule size was observed, particularly among cases with GH-type CNA, where every additional centimeter of nodule size increased the malignancy odds by 1.9 (95% CI 1.3-2.7; P = 0.001). In summary, the results of this study demonstrate that CNA characteristic of HCC also occur in HCA, although with lower frequency, and probability of cancer in nodules with CNA increases with nodule size. Detection of CNA, in conjunction with other mutations and nodule size, is helpful in predicting malignancy in thyroid nodules.

Background: Poorly differentiated thyroid cancer (PDTC) is a rare, follicular cell-derived neoplasm with an unfavorable prognosis. The oncocytic variant of PDTC may be associated with even more adverse outcome than classical PDTC cases, but its specific molecular features are largely unknown. Our aim was to explore the immune-related gene expression profile of oncocytic and classical PDTC, in correlation with clinical and pathological characteristics (including programmed death ligand 1 [PD-L1] expression) and outcome, and in comparison with a control group of well-differentiated follicular carcinomas (WDFCs), including conventional follicular carcinomas (FTCs) and Hürthle cell carcinomas (HCCs)., Methods: A retrospective series of 48 PDTCs and 24 WDFCs was analyzed by means of NanoString technology employing the nCounter PanCancer Immune Profiling panel. Gene expression data were validated using quantitative real-time polymerase chain reaction., Results: Oncocytic PDTCs showed a specific immune-related gene expression profile, with higher expression of LAIR2, CD274, DEFB1, IRAK1, CAMP, LCN2, LY96, and APOE, and lower expression of NOD1, as compared to conventional PDTCs. This molecular signature was associated with increased intratumoral lymphocytic infiltration, PD-L1 expression, and adverse outcome. Three of these genes, CD274, DEFB1, and IRAK1, as well as PD-L1 expression, were also the hallmarks of HCCs as compared to FTCs. By contrast, the panel of genes differentially regulated in PDTCs as compared to WDFCs was unrelated to the oncocytic phenotype., Conclusions: Our results revealed a distinctive immune-related gene expression profile of oncocytic PDTC and confirmed a more aggressive outcome in this cancer subtype. These findings may provide guidance when exploring novel immunotherapeutic options for oncocytic PDTC patients., (© Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: The hallmarks of type 2 diabetes (T2D) are hyperglycaemia and insulin resistance. These factors, at the cellular level, are associated with mitochondrial dysfunction and increased glucose uptake. Such events are poorly explored in the context of the salivary glands. In this study, we present a series of eight cases of a distinct salivary gland lesion characterised by multiple oncocytic cysts, and we provide new pathological insights regarding its pathogenesis., Methods and Results: Seven patients (87.5%) had confirmed T2D, and obesity was identified in five (62.5%) patients. Clinically, the patients showed bilateral parotid gland swelling with recurrent episodes of pain and enlargement. Imaging examination revealed multiple cystic lesions in both parotid glands. Microscopically, the parotid glands showed multiple cysts of different sizes, lined by oncocytic epithelial cells. Intraluminally, strongly eosinophilic glass-like crystalloid material was observed. Immunohistochemical studies were performed, and the most notable finding was glucose transporter 1 (GLUT1) overexpression in the oncocytic cysts which is not observed in any other oncocytic lesion of patients without T2D. In addition, high expressions of mitochondrial antigen, fission 1 protein and mitofusin-2 were observed in the oncocytic epithelium of the cysts. Furthermore, most of the oncocytic cysts showed a pattern of cytokeratin expression consistent with striated ducts., Conclusions: These results strongly suggest that T2D is associated with alterations in GLUT1 expression in the cells of striated ducts with mitochondrial dysfunction, causing a hyperplastic process characterised by multiple oncocytic cysts. For this lesion, the designation of 'diabetes-associated-bilateral multiple oncocytic cysts of the parotid gland' is proposed., (© 2019 John Wiley & Sons Ltd.)

Chronic immunosuppression is known to cause an increased risk of cancers in organ transplant recipients leading to the rise in morbidity and mortality among these patients. Recent studies have observed that thyroid lesions are more frequently encountered in kidney transplant recipients. A 45-year-old woman with history of chronic hypertension, kidney transplant and graft failure, was admitted for assessment for a second renal transplant and detected to have a thyroid nodule by ultrasound (US). A fine needle aspirate (FNA) on the nodule was reported as Hurthle cell neoplasm. Histopathology revealed a Hurthle cell adenoma with an incidental micro papillary carcinoma. On follow up a year later, US investigation revealed another nodule in the inferior pole of the remnant lobe of thyroid. FNA showed sheets of uniform small round cells arranged in micro follicles, intermixed with Hurthle-like cells with absence of colloid, raising the possibility of a parathyroid lesion. Biochemical tests, clinical history, cytomorphological, immunocytochemical and biochemical tests supported a parathyroid adenoma. Advancements in diagnostic techniques and management strategies have not only improved survival rates in patients with chronic renal disease but have also identified an increasing number of multiple primary tumors in these patients. Thyroid lesions have cytomorphological similarities and may masquerade parathyroid neoplasms. Regular thyroid screening in post- transplant patients, meticulous pathological examination and parathormone assay are crucial in the early diagnosis, management and prevention of morbidity and mortality in these patients. Keywords: Fine needle aspiration, kidney transplant, Hurthle cell neoplasm, parathyroid adenoma, micropapillary carcinoma.

Background: Molecular tests such as the Afirma gene expression classifier (GEC) and mutational panels (such as ThyroSeq) have been introduced to help risk stratify cytologically indeterminate thyroid nodules with the aim to reduce the number of unnecessary thyroidectomies. Some reports have suggested that samples with Hurthle cell predominance have higher false-positive rates on GEC testing, but data are limited., Methods: We reviewed thyroid nodules with indeterminate (Bethesda III/IV) cytology at our institution. Patient demographics, cytologic and histologic diagnoses (where available), and molecular test results were collected., Results: GEC was performed on 202 nodules, and ThyroSeq was performed on 81 nodules. In the GEC cohort, 66% of nodules with Hurthle cell predominance yielded "suspicious" result vs 46% of nodules without Hurthle cell predominance, with risk of malignancy (ROM) for surgically resected nodules of 16% and 33%, respectively. In ThyroSeq cohort, 8% of nodules with Hurthle cell predominance yielded a high-risk mutation vs 19% of nodules without Hurthle cell predominance, with ROM of 50% and 33%, respectively., Conclusions: For ThyroSeq molecular panel, while it did not appear that there was an increase in rate of high-risk mutations detected in the samples with Hurthle cell predominance, small numbers limit the generalizability of these results. For the GEC cohort, indeterminate thyroid nodules with predominance of Hurthle cells showed an increased rate of "suspicious" results compared to samples without Hurthle cell predominance. The ROM for GEC "suspicious" nodules with Hurthle cell predominance on surgical resection was lower in our study. Repeat FNA may be of use in patients with these types of nodules. In the context of a Hurthle cell predominant lesion, positive results on molecular testing may not carry a high rate of malignancy., (© 2019 Wiley Periodicals, Inc.)

Background: Hürthle cell lesions often pose diagnostic challenges, despite their common occurrence on thyroid fine-needle aspiration cytology (FNAC). The associated molecular alterations are also not well understood. Therefore, our study aimed to delineate the molecular profile of Hürthle cell lesions classified as Bethesda Categories III or IV (atypia of undetermined significance (AUS) or suspicious for follicular neoplasm (SFN)) on FNAC and to correlate this molecular profile with surgical resection findings., Methods: This study consisted of 188 Hürthle cell lesions with indeterminate cytology and ThyroSeq® v2/v3 molecular testing results. Surgical follow-up was available for 33 cases., Results: The majority of indeterminate Hürthle cell lesions had negative ThyroSeq® results (61%) and were benign on available surgical follow-up. The most prevalent mutations involved the RAS gene (21%), which were associated with benign lesions, non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and malignancy. The remaining mutations involved less than 18% of the cases, including PAX8/PPARG (3.7%), TSHR (3.7%), EIF1AX (2.7%), MET (2.1%), PTEN (1.6%), clonal copy number alteration (1.6%), TERT (1.1%), and 0.5% each of GNAS, PIK3CA, and TP53 mutations. On follow-up, 45% were benign, 24% were NIFTP, and 30% were malignant. The malignant cases had different molecular alterations., Conclusion: No single molecular alteration defines cytologically indeterminate Hürthle cell lesions; the majority of cases have low-risk or no molecular alterations and are benign on follow-up. These findings suggest that molecular testing may be useful, but is not definitive, in determining which cases may be managed conservatively; additional studies are needed to fully determine the negative predictive value in ruling out malignancy., (© 2019 Wiley Periodicals, Inc.)

Incidental thyroid uptake is found in approximately 2.5% of patients who undergo FDG PET for nonthyroid malignancy; approximately a third of the FDG PET thyroid incidentalomas are malignant, including primary thyroid malignancies and metastasis. We describe a 50-year-old woman, a potential heart transplant candidate with history of breast cancer, who was found by FDG PET/CT to harbor a large thyroid mass with intense FDG uptake. Biopsy and molecular study demonstrated that the thyroid mass was a Hürthle cell adenoma. This case highlights that Hürthle cell neoplasm should be included in the differential diagnosis of a thyroid nodule with very high FDG avidity.

The aim of this study is to investigate the changes with age on morphology and sex hormone receptor expression in the mammary glands of male Sprague-Dawley rats, focusing on male-specific cells, "oxyphilic cells", observed after sexual maturity. The mammary glands of male rats at 14, 21, 35, 50, 75 and 100 days old were examined by gross observation, microscopic observation using whole mount specimens, histological and immunohistochemical sections. Grossly, mammary glands showed brown color at 50-100 days old. In whole mount specimens, terminal end buds (TEBs) were observed at 14-50 days old and the number of TEBs was highest at 35 days old. Histologically, the male mammary glands contained small epithelial cells with scanty cytoplasm at 14-35 days old while ductal and lobular epithelial cells were changed into oxyphilic cells with abundant cytoplasm at 50-100 days old. Immunohistochemicaly, androgen receptor (AR), estrogen receptor (ER) and progesterone receptor (PgR) expressions were found in both mammary glands found at a young age and oxyphilic cells. In oxyphilic cells, AR expression was dominant compared to ER and PgR expressions and increased with age. From these results, the development at 50-100 days old might be strongly related to AR. Ultrastructural observation of oxyphilic cells confirmed a number of lipid droplets, deformed and/or enlarged mitochondria, lysosomes and peroxisomes in their cytoplasm.

SHPT is one of the most common complications of CKD-MBD. Recent studies indicate that oxyphil cell proliferation is related to SHPT progression, while not inhibited by current treatments. The aim of this study was to analyze the correlation between oxyphil cell and clinical indicators in SHPT, further explore the protein expression differences of oxyphil cell. Among 33 MHD patients, 84.8% patients have one or more oxyphil dominant glands and the overall oxyphil cells proportion was 39.5 ± 16.3%. Univariate correlation and multivariable linear regression model showed that oral calcitriol dosage and treatment duration were independently correlated to oxyphil cell ratio. Proteomic study showed that mitochondrial protein, protein synthesis, and cell cycle regulation were significantly altered in oxyphil cell nodules. DBP was downregulated in oxyphil nodules on protein level, which may contribute to calcitriol resistance by reducing vitamin D transport. Through KEGG and PPI network analysis, Wnt signaling, TGF-β, ubiquitin mediated proteolysis and cell cycle pathways were significantly enriched in oxyphil cell nodules. Among which, MIF-CUL1 axis was significantly increased. These results suggest that the limitations of vitamin D in SHPT treatment is closely related to oxyphil cell and may be attributed to the dysregulation of vitamin D transport and ubiquitin regulation of oxyphil cell., Significance: Secondary hyperparathyroidism in end stage renal patients is one of the major challenges nephrology field faces. Emerging data indicate that oxyphil cell may participate in the pathophysiology of secondary hyperparathyroidism, while both calcimimetics and vitamin D receptor activators treatments are underperformed in controlling oxyphil cell proliferation. In the present study, we validated that the proliferation of oxyphil cells is associated with calcitriol treatment, and discovered that oxyphil cell nodules were significantly different from chief cells nodules in protein expression of mitochondria, protein synthesis and cell cycle regulation. It is noteworthy that DBP was downregulated in oxyphil nodules on protein level and may therefore participate in the resistance of calcitriol therapy by reducing the vitamin D transport capacity. Wnt signaling, TGF-β, ubiquitin mediated proteolysis and cell cycle pathways were significantly enriched in oxyphil cell nodules, among which, MIF-CUL1 axis may play an important role in the regulation of oxyphil proliferation and calcitriol resistance through ubiquitin mediated proteolysis. These results suggest that calcitriol treatment has limitations in oxyphil cell predominant SHPT, which may be attributed to the dysregulation of vitamin D transport and ubiquitin regulation of oxyphil cell, and the influence of microenvironment in uremia status may be the underlying reason., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The present study was designed to evaluate the participation and utility of Hǘrtle cells morphological requirment and transformation under Hashimoto autoimmune thyroiditis versus Riedel´s struma. Several markers have been evaluated to detect induced activities of Hǘrtle cells. Study subject - specimens (tissue fragments) collected from TG surgery (thyroidectomy) for mollecular (receptor) diagnosis of Hǘrtle cells activities using routine histological and immunohistochemical samples. 89 cases were selected in Hashimoto thyroiditis diagnosis with Hǘrtle cells history (adenoma and adenomatous grouth of oncocytes). Markers as: TSH receptors, TTF-1, S-100 protein, also anti-TPO and anti-TG levels in blood plasm were detected. It was shown that solid cell claster-nests like agregation of oncocytes and adenomatous growth foci in parafollicular areas with anti-TPO and anti-TG antibodies levels arising while Riedel´s struma shown only large intra- and extra glandular inflammatory proliferative fibrosing process. Large positive expression of TTF-1 and S-100 protein and the negative reaction of TSH receptor factor suggest that Thyroid parenchyma disorganization and mollecular biological atypia with Hǘrtle cells are proceses due to hypothyreoidismus, as well as neuroectodermal cells prominent activities in 70% of Hashimoto cases.

Deep esophageal glands play a vital role in the protection and regeneration of the esophageal mucosa. Conditions such as gastroesophageal reflux disease and Barrett's esophagus have been associated with a change in the usual glands by oncocytic metaplasia. However, little is known regarding the function of oncocytes or the relevance of this metaplastic change in the human esophagus. We hypothesized that oncocytes of deep esophageal glands also express markers characteristic of a ductal epithelial phenotype because similar oncocytes have been described as part of large ductal epithelial cells in salivary glands. We used immunohistochemical stains to define structural, functional, proliferative, and potential stem/progenitor characteristics of oncocytes. Oncocytes did not express mucins or lysozyme C, two molecules found in mucous cells and used for antimicrobial defense. Oncocytes did not express CK5, a cytokeratin found in myoepithelial cells and basal epithelial cells, but expressed CK7, a cytokeratin found in intralobular ductal epithelial cells and luminal epithelial cells of the main duct. Oncocytes expressed cystic fibrosis transmembrane conductance regulator and sodium/potassium ATPase, ion channels that play a role in bicarbonate secretion. Membrane-bound beta-catenin was detected in oncocytes, but these cells did not express the proliferative marker Ki67. Approximately, a third of oncocytes expressed SOX9 and p63, transcription factors expressed in epithelial progenitor cells in multiple organs. Moreover, oncocytes expressed CD44, a transmembrane Glycoprotein expressed in cancer stem cells. Taken together, our data show that oncocytes express markers of intralobular ductal epithelial cells and luminal epithelial cells of the main duct. Additionally, our observations suggest that oncocytes act as epithelial progenitor cells and play a role in bicarbonate secretion. Since oncocytic metaplasia is associated with conditions of chronic acid injury, it is possible that oncocytes replace the mucous cells in deep esophageal glands (dEG) as an adaptive change to counteract injury from acid reflux. The marker characterization suggests that oncocytes may originate from transdifferentiation of myoepithelial and mucous cells. This transdifferentiation might lead to an overall decrease of mucins production and secretion by the dEG and a subsequent reduction of the protection conferred by the viscoelastic mucous layer., (© 2015 International Society for Diseases of the Esophagus.)

Oxyphil cell parathyroid adenomas (OPA) are considered to be an uncommon cause of primary hyperparathyroidism (PHPT), and were historically thought to be clinically silent. It has been our clinical impression that these adenomas present more often than previously thought and may manifest a more severe form of primary hyperparathyroidism than classical adenoma. The aim of this study was to describe the incidence and clinical presentation of OPA. An observational case-control study was undertaken. The study group comprised patients undergoing parathyroidectomy for PHPT where the final pathology confirmed OPA. The controls were made up of an age- and sex-matched group of patients having parathyroidectomy in the same time period where the final pathology confirmed a classical or non-oxyphil adenoma. OPA were defined as parathyroid tumours containing >75% oxyphilic cells. The OPA cases were obtained by reviewing all histopathology slides over an 11-year period (2002-12) where the reports contained the words 'oxyphil' or 'oxyphilic' parathyroid adenomas. These were then reviewed by two independent pathologists to confirm a diagnosis of OPA. The primary outcome measures were preoperative serum calcium and parathyroid hormone (PTH) levels. Secondary outcome measures were symptoms at presentation, accuracy of preoperative localization studies, parathyroid gland weight following surgery, and type of surgery undertaken. In the period 2002-2012, 2739 patients underwent surgery for PHPT. Following pathological review, 91 cases were confirmed as being OPA and formed the study group. A control group (n = 91) from the same period was selected following matching on the basis of age at presentation and sex. OPA were associated with higher preoperative serum calcium (10.84 versus 10.48 mg/dL, p < 0.001) and parathyroid hormone (139 versus 64 ng/L, p < 0.001). At presentation, a lower proportion of OPA cases had asymptomatic disease (15 versus 29%, p = 0.03). There was a trend toward a higher rate of renal calculi at presentation in the OPA group (9 versus 3%, p = 0.07). Preoperative ultrasound was less accurate in localization of OPA when compared with classical adenoma. The rate of minimally invasive surgery was 67% for OPA and 78% for the control group (p = 0.06). All patients were cured of hypercalcaemia at 6-month follow up. There was no significant difference in the weight of removed parathyroid tissue between the groups (868 mg for OPA versus 789 mg for the control group, p = 0.6). OPA are frequently symptomatic and are associated with higher preoperative serum calcium and parathyroid hormone levels than classical types of parathyroid adenomas. OPA are less likely to be localised on preoperative ultrasound examination.

Background: The recently introduced Afirma gene expression classifier (AGEC) provides binary results (benign or suspicious) to guide management of cytologically indeterminate thyroid nodules. The AGEC is intended to reduce unnecessary surgeries for benign nodules, and management algorithms favor surgery for suspicious results. Limited data are available on the performance of this test for Hürthle cell nodules (HCNs). This study hypothesized that a predominance of Hürthle cells leads to an increased rate of suspicious AGEC results with a potential for overtreatment, despite a relatively low risk of malignancy., Methods: The pathology databases from three tertiary care facilities were queried from 2010 to 2014 for fine-needle aspirates (FNAs) diagnosed as suspicious for Hürthle cell neoplasm (SHCN) or atypia of undetermined significance/follicular lesion of undetermined significance concerning for Hürthle cell neoplasm (AFHCN). Cytology diagnoses were rendered internally prior to AGEC testing. The patient demographics, FNA diagnosis, AGEC result, surgical procedure, and pathologic outcomes were recorded., Results: The cohort consisted of 134 patients with HCNs. Prior to AGEC availability, 62 patients underwent surgery: 81% (50/62) of patients had surgery, and 34% (17/50) of the resected index nodules were malignant. After introduction of the AGEC, 72 patients underwent AGEC testing: 65% (47/72) of patients had surgery, and 13% (6/46) of the resected nodules were malignant. Thirty-two percent (23/72) of patients had a benign AGEC result and did not undergo surgery, and 4% (3/72) had surgery despite a benign AGEC result with benign final pathology, whereas 63% (45/72) of patients had suspicious AGEC results, with 96% of these patients (43/45) undergoing surgery, and 14% (6/43) of these index nodules were malignant., Conclusions: While 32% of tested patients declined surgery based on a benign AGEC, 86% of patients with suspicious AGEC findings had unnecessary surgery, reflecting a substantially lower rate of malignancy from what was previously reported for all indeterminate nodules. Given the approximate pretest malignancy risk of 25-35% for an FNA diagnosis of SHCN or AFHCN, a suspicious AGEC diagnosis does not increase the probability of malignancy in an HCN, and patients should be counseled accordingly.

Oxyphil cell transformation of epithelial cells due to the accumulation of mitochondria occurs often during cellular aging. To understand the pathogenic mechanisms, we studied mitochondrial DNA (mtDNA) alterations in the three cell types of the parathyroids using multiplex real-time PCR and next-generation sequencing. mtDNA was analyzed from cytochrome c oxidase (COX)-positive and COX-negative areas of 19 parathyroids. Mitochondria-rich pre-oxyphil/oxyphil cells were more prone to develop COX defects than the mitochondria-poor clear chief cells (P < 0.001). mtDNA increased approximately 2.5-fold from clear chief to oxyphil cells. In COX deficiency, the increase was even more pronounced, and COX-negative oxyphil cells had approximately two times more mtDNA than COX-positive oxyphil cells (P < 0.001), illustrating the influence of COX deficiency on mtDNA biosynthesis, probably as a consequence of insufficient ATP synthesis. Next-generation sequencing revealed a broad spectrum of putative pathogenic mtDNA point mutations affecting NADH dehydrogenase and COX genes as well as regulatory elements of mtDNA. NADH dehydrogenase gene mutations preferentially accumulated in COX-positive pre-oxyphil/oxyphil cells and, therefore, could be essential for inducing oxyphil cell transformation by increasing mtDNA/mitochondrial biogenesis. In contrast, COX-negative cells predominantly harbored mutations in the MT-CO1 and MT-CO3 genes and in regulatory mtDNA elements, but only rarely NADH dehydrogenase mutations. Thus, multiple hits in NADH dehydrogenase and COX activity-impairing genes represent the molecular basis of oxyphil cell transformation in the parathyroids.

The role Hsp60 might play in various inflammatory and autoimmune diseases is under investigation, but little information exists pertaining to Hashimoto's thyroiditis (HT). With the aim to fill this gap, in the present work, we directed our attention to Hsp60 participation in HT pathogenesis. We found Hsp60 levels increased in the blood of HT patients compared to controls. The chaperonin was immunolocalized in thyroid tissue specimens from patients with HT, both in thyrocytes and oncocytes (Hurthle cells) with higher levels compared to controls (goiter). In oncocytes, we found Hsp60 not only in the cytoplasm but also on the plasma membrane, as shown by double immunofluorescence performed on fine needle aspiration cytology. By bioinformatics, we found regions in the Hsp60 molecule with remarkable structural similarity with the thyroglobulin (TG) and thyroid peroxidase (TPO) molecules, which supports the notion that autoantibodies against TG and TPO are likely to recognize Hsp60 on the plasma membrane of oncocytes. This was also supported by data obtained by ELISA, showing that anti-TG and anti-TPO antibodies cross-react with human recombinant Hsp60. Antibody-antigen (Hsp60) reaction on the cell surface could very well mediate thyroid cell damage and destruction, perpetuating inflammation. Experiments with recombinant Hsp60 did not show stimulation of cytokine production by peripheral blood mononuclear cells from HT patients. All together, these results led us to hypothesize that Hsp60 may be an active player in HT pathogenesis via an antibody-mediated immune mechanism.

Parathyroid adenomas (PAs) causing primary hyperparathyroidism (PHPT) are histologically heterogeneous yet have been historically viewed as largely monotypic entities arising from clonal expansion of a single transformed progenitor. Using flow cytometric analysis of resected adenomatous parathyroid glands, we have isolated and characterized chief cells, oxyphil cells, and tumor-infiltrating lymphocytes. The parathyroid chief and oxyphil cells produce parathyroid hormone (PTH), express the calcium-sensing receptor (CASR), and mobilize intracellular calcium in response to CASR activation. Parathyroid tumor infiltrating lymphocytes are T cells by immunophenotyping. Under normocalcemic conditions, oxyphil cells produce ∼50% more PTH than do chief cells, yet display significantly greater PTH suppression and calcium flux response to elevated calcium. In contrast, CASR expression and localization are equivalent in the respective parathyroid cell populations. Analysis of tumor clonality using X-linked inactivation assays in a patient-matched series of intact tumors, preparatively isolated oxyphil and chief cells, and laser-captured microdissected PA specimens demonstrate polyclonality in 5 of 14 cases. These data demonstrate the presence of functionally distinct oxyphil and chief cells within parathyroid primary adenomas and provide evidence that primary PA can arise by both clonal and polyclonal mechanisms. The clonal differences, biochemical activity, and relative abundance of these parathyroid adenoma subpopulations likely reflect distinct mechanisms of disease in PHPT.

Adrenocortical carcinosarcomas are rare aggressive neoplasms; only a few have been reported to date, all with dismal prognosis. These were reported as having varying morphology. We have encountered a case of adrenal carcinosarcoma with an undifferentiated component bearing similarities to primitive neuroectodermal tumors and other areas of oncocytic differentiation. The 48-year-old woman patient presented with abdominal pain and unintended, excessive weight loss. Computed tomographic imaging revealed a tumor located adjacent to the liver and kidney necessitating a partial nephrectomy and hepatectomy. Histologically, the tumor exhibited malignant features. Melan-A, inhibin, calretinin, cytokeratin AE1/AE3, synaptophysin, and neuron-specific enolase were positive immunohistochemically. The patient developed metastasis within 2 months of surgery and is currently alive with disease after chemotherapy. Adrenal carcinosarcoma is a rare highly aggressive malignancy with a wide morphologic spectrum. Recognition of variant morphology and applying correct immunohistochemical studies will aid in reaching an accurate diagnosis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Epithelial myoepithelial carcinoma (EMCa) is a rare but well characterized biphasic salivary gland malignancy with several variant morphologies. Oncocytic and apocrine EMCa are uncommon variants that constitute up to 8 % of all EMCa. Both variants invoke an eosinophilic or oncocytic differential diagnosis and challenge the traditional requirement of clear myoepithelial cells for EMCa. Oncocytic EMCa occurs in patients a decade older than conventional EMCa. This variant is often papillary with calcification and associated with sebaceous components and occurs in older individuals. Apocrine EMCa is named for its apocrine ductal component, which may be mistaken for salivary duct carcinoma. In this variant, the epithelial component often shows overgrowth in a cribriform or even solid pattern and is immunophenotypically defined by androgen receptor and gross cystic disease fluid protein 15 positivity. The most important aspect of differentiating both oncocytic and apocrine EMCa from other salivary oncocytic tumors is recognition of the biphasic nature of these variants and confirmation that the abluminal outer layer consists of plump, 'activated' myoepithelial cells, regardless of tinctorial characteristics. Both oncocytic and apocrine EMCa behave very indolently in the limited literature to date.

Objective: The most difficult thyroid tumors to be diagnosed by cytology and histology are conventional follicular carcinomas (cFTCs) and oncocytic follicular carcinomas (oFTCs). Several microRNAs (miRNAs) have been previously found to be consistently deregulated in papillary thyroid carcinomas; however, very limited information is available for cFTC and oFTC. The aim of this study was to explore miRNA deregulation and find candidate miRNA markers for follicular carcinomas that can be used diagnostically., Design: Thirty-eight follicular thyroid carcinomas (21 cFTCs, 17 oFTCs) and 10 normal thyroid tissue samples were studied for expression of 381 miRNAs using human microarray assays. Expression of deregulated miRNAs was confirmed by individual RT-PCR assays in all samples. In addition, 11 follicular adenomas, two hyperplastic nodules (HNs), and 19 fine-needle aspiration samples were studied for expression of novel miRNA markers detected in this study., Results: The unsupervised hierarchical clustering analysis demonstrated individual clusters for cFTC and oFTC, indicating the difference in miRNA expression between these tumor types. Both cFTCs and oFTCs showed an up-regulation of miR-182/-183/-221/-222/-125a-3p and a down-regulation of miR-542-5p/-574-3p/-455/-199a. Novel miRNA (miR-885-5p) was found to be strongly up-regulated (>40-fold) in oFTCs but not in cFTCs, follicular adenomas, and HNs. The classification and regression tree algorithm applied to fine-needle aspiration samples demonstrated that three dysregulated miRNAs (miR-885-5p/-221/-574-3p) allowed distinguishing follicular thyroid carcinomas from benign HNs with high accuracy., Conclusions: In this study we demonstrate that different histopathological types of follicular thyroid carcinomas have distinct miRNA expression profiles. MiR-885-5p is highly up-regulated in oncocytic follicular carcinomas and may serve as a diagnostic marker for these tumors. A small set of deregulated miRNAs allows for an accurate discrimination between follicular carcinomas and hyperplastic nodules and can be used diagnostically in fine-needle aspiration biopsies.

Hürthle cells have long been described in Hashimoto thyroiditis but remain of undetermined significance. We have previously shown that Hürthle cells and hypothyroidism develop in C57BL/6J mice expressing interferon-γ (IFNγ) in the thyroid. To assess the influence of genetic backgrounds on Hürthle cell development, we crossed C57BL/6J IFNγ transgenic mice to 14 strains and analyzed thyroid histopathology and function in a cohort of 389 mice (225 transgenic and 164 wild type) using a multiple linear regression model that also included strain, sex, genotype, and major histocompatibility complex haplotype. We then queried the Johns Hopkins surgical pathology electronic archive for "Hashimoto" and/or "thyroiditis" keywords, reviewed the reports, and reexamined the Hashimoto slides. Hürthle cells were markedly affected by the genetic background: they were prominent and associated with hypothyroidism in the C57BL/6J, C57BL/6ByJ, C57BL/10J, C57BLKS/J, C57L/J, C58/J, and BPN/3J IFNγ transgenic strains, whereas they are mild or absent in the BPH/2J, BPL/1J, LP/J, CBA/J, Balb/cJ, DBA/1J, and NOD/ShiLtJ strains. Hürthle cells were the strongest predictor of hypothyroidism after adjusting for all the other covariates in the regression model. Interestingly, transgenic mice of the BPL/1J, DBA/1J, and NOD/ShiLtJ strains developed a marked accumulation of intrathyroidal brown adipocytes that was significantly associated with improved thyroid function. Hürthle cells were mentioned in 23% of the Hashimoto reports but increased to 79% upon our slide review. This study reports a novel association of Hürhtle cells and brown adipocytes on thyroid function that should prompt a reconsideration of their significance and role in pathogenesis of autoimmune thyroiditis.

Context: Parathyroid oxyphil cells, whose function is unknown, are thought to be derived from chief cells. Oxyphil cells increase in number in parathyroid glands of patients with chronic kidney disease (CKD) and are even more abundant in patients receiving treatment for hyperparathyroidism with calcitriol and/or the calcimimetic cinacalcet., Objective: We examined oxyphil and chief cells of parathyroid glands of CKD patients for differential expression of genes important to parathyroid function., Design/setting/participants: Parathyroid tissue from CKD patients with refractory hyperparathyroidism was immunostained for gene expression studies., Main Outcome Measure: Immunostaining for PTH, PTHrP, calcium-sensing receptor, glial cells missing 2, vitamin D receptor, 25-hydroxyvitamin D-1α-hydroxylase, and cytochrome c was quantified and expression reported for oxyphil and chief cells., Results: Expression of all proteins analyzed, except for the vitamin D receptor, was higher in oxyphil cells than in chief cells., Conclusion: Human parathyroid oxyphil cells express parathyroid-relevant genes found in the chief cells and have the potential to produce additional autocrine/paracrine factors, such as PTHrP and calcitriol. Additional studies are warranted to define the secretory properties of these cells and clarify their role in parathyroid pathophysiology.

Background: Cowden syndrome (CS) is an autosomal dominant disorder characterised by macrocephaly, specific mucocutaneous features and predisposition to benign and malignant tumours. Detectable mutations in the PTEN gene account for 80-85% of cases., Methods/results: Here, the authors report a patient with macrocephaly and typical CS mucocutaneous features who developed dysplastic cerebellar gangliocytoma and two synchronous thyroid cancers of papillary and oncocytic type, in whom a germline 500-Kb deletion on chromosome 10q23 including PTEN was detected. Molecular characterisation of thyroid cancer led to the identification of the oncogenic BRAFV600E mutation in the papillary carcinoma. BRAFV600E has been proposed to cause cancer only in the presence of a tumour-suppressor mutation, which, in this case, could be the PTEN deletion. In the oncocytic carcinoma, a large deletion in the mitochondrial-DNA-encoded MTND1 was found, associated with respiratory complex I disassembly, which was subsequently shown to be a constitutional, de novo genetic lesion., Conclusions: This is the first reported case of a patient with CS carrying constitutional deletions in both the nuclear and the mitochondrial genome that might help elucidate some aspects of CS pathogenesis.

The review briefly describes the evolution of hypotheses about cronic thyroiditis, the escape of colloid hypothesis, basement membrane destruction, the auto-immune theory and the role of disregulatory genes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

A case of multifocal nodular oncocytic hyperplasia (MNOH) of the bilateral parotid gland is presented. An 80-year-old woman was admitted to hospital because of painless swellings in bilateral parotid regions. Histologically, the nodular lesion had incomplete capsules and engulfed the surrounding parotid gland at the periphery. The lesions were mostly composed of clear cells, while the peripheries of the lesions had typical oncocytic cells with abundant fine granules. The histological existence of the clear cell component in the lesions led to misdiagnoses of other clear cell neoplasms. However, this case had multiple nodules in bilateral glands. No evidence of malignant histological findings was found. Moreover, the clear cells, as well as the oncocytic cells, were demonstrated to have mitochondria and glycogen in their cytoplasm using special staining. Based on these findings, the diagnosis of this case was MNOH in the parotid gland. We also discuss the differential diagnosis for clear cell lesions., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Pediatric adrenocortical carcinoma is extremely rare with a prevalence of 0.3 per million. Adrenocortical neoplasms in children usually present with one of the endocrine abnormalities. Adrenocortical neoplasms cannot be easily diagnosed on cytopathology; hence, the cytomorphological features posing diagnostic dilemmas are discussed in a pediatric patient presenting with palpable abdominal mass and virilization. Fine-needle aspiration smears were cellular showing cells in cohesive clusters adhering to central core of capillaries exhibiting an endocrine vascular pattern along with single cells and stripped nuclei. Cells were polygonal in shape and had abundant cytoplasm with well-defined borders and round eccentric nuclei with prominent nucleoli. Marked anisonucleosis was also noted. Few cells showed abundant granular cytoplasm resembling oncocytes. Many bizarre and multinucleated cells, few mitotic figures, and necrosis were also seen. Hematoxylin and eosin-stained sections of tumor biopsy suggested possibility of adrenocortical neoplasm. A panel of immunohistochemical markers were used to exclude possibility of renal cell carcinoma (RCC) and pheochromocytoma that showed vimentin (+), cytokeratin (-), inhibin-α (+), neuron-specific enolase (focally +), and chromogranin (-). The Ki67 index was 15%, and P53 was strongly positive. It is difficult to distinguish adrenocortical neoplasm, RCC, and pheochromocytoma on cytology because of overlapping features; hence, important cytological features which help in distinguishing between the three are discussed.

Oncocytic breast carcinomas are tumors composed of no fewer than 70% of oncocytic cells (World Health Organization). The purpose of this study was to determine the frequency, morphologic, immunohistochemical, and clinical features of invasive oncocytic carcinoma in a large series. Twenty-eight cases of putative oncocytic breast carcinoma (selected cases group) and 76 consecutive cases of invasive breast carcinoma (consecutive cases group) were analyzed. Immunohistochemistry for mitochondria, gross cystic disease fluid protein 15, chromogranin, estrogen receptor, progesterone receptor, androgen receptor, HER2/Neu, cytokeratin 7, cytokeratin 14, epithelial membrane antigen, and differentiation cluster 68 was performed. Score for mitochondria was based on intensity and percentage of immunopositive cells. Classes were as follows: (1) oncocytic carcinoma: at least 70%, 3+; (2) mitochondrion-rich carcinoma: 50% to 70%, 3+, or more than 50%, 2+; and (3) all the other cases were referred to as invasive breast carcinoma. Ultrastructural examination was available for 6 cases of oncocytic carcinoma. Morphologic and immunohistochemical features of the 3 groups were compared using Fisher exact test (P < .05). For overall survival analysis, Kaplan-Maier curves were compared using log-rank and Wilcoxon tests (P < .05). Our results suggest that oncocytic breast carcinoma is a morphologic entity with distinctive histologic and ultrastructural features. Mitochondrion-rich carcinomas are histologically similar to oncocytic carcinomas and constitute 19.7% of all invasive carcinomas, indicating that cytoplasmic eosinophilia in breast cancer cells is often due to accumulation of mitochondria. Oncocytic carcinomas and mitochondrion-rich carcinomas are more often grade III tumors and show human epidermal growth factor receptor 2 overexpression. Clinical features and overall survival of oncocytic carcinomas are not distinctive because they are similar to those of the other cases when matched for grade and stage., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Dicer is a type III ribonuclease required for the biogenesis of microRNAs (miRNAs), a class of small non-coding RNAs regulating gene expression at the post-transcriptional level. To explore the functional role of miRNAs in thyroid gland function, we generated a thyrocyte-specific Dicer conditional knockout mouse. Here we show that development and early differentiation of the thyroid gland are not affected by the absence of Dicer, while severe hypothyroidism gradually develops after birth, leading to reduced body weight and shortened life span. Histological and molecular characterization of knockout mice reveals a dramatic loss of the thyroid gland follicular architecture associated with functional aberrations and down-regulation of several differentiation markers. The data presented in this study show for the first time that an intact miRNAs processing machinery is essential for thyroid physiology, suggesting that deregulation of specific miRNAs could be also involved in human thyroid dysfunctions.

Herein, we report an unusual choroid plexus carcinoma with extensive oncocytic transformation. A 13-month-old girl presented with acute lethargy which quickly progressed to coma. A CT scan of the head revealed impending herniation due to hemorrhage within an intracranial tumor. An MRI scan showed a large, partly cystic and highly vascular left lateral ventricular mass. A near total resection was achieved. Microsections revealed a WHO Grade III choroid plexus carcinoma with extensive oncocyti c transformation. A minor portion of the moderately to poorly differentiated tumor exhibited classical microscopic features of choroid plexus carcinoma, including marked nuclear atypia, brisk mitotic activity (78/10 HPF), a high MIB-1 labeling index (44%) and zones of necrosis. In contrast, the large, eosinophilic, cytologically malignant but granular-appearing oncocytes comprising the majority of the lesion showed scant (1/10 HPF) mitotic activity and only a low MIB-1 labeling index (5%). A subsequent recurrence at 1 year consisted entirely of non-oncocytic tumor. Choroid plexus carcinoma with oncocytic transformation has not been previously reported. The remarkable extent of this alteration and its clinical significance remains to be determined.

Aims: To separate true oncocytic neoplasms from mitochondrion-rich non-oncocytic lesions based on the intracellular relationship between major cell organelles, and to establish the diagnostic and clinical relevance of this distinction., Methods and Results: Tissue samples from 276 follicular adenomas, 194 follicular carcinomas, 162 normal thyroids and 296 non-neoplastic lesions were classified as conventional, mitochondrion-rich or oncocytic based on the immunohistochemically assessed quantity and intracellular distribution of mitochondria and endoplasmic reticulum (ER) and nuclear position. Pathological and clinical features were compared among the groups. In oncocytes, densely packed mitochondria resulted in homogeneous immunolabelling of basal cytoplasmic regions, whereas ER and the nuclei were typically displaced to the apical position. This aberrant organelle distribution was not observed in non-oncocytes, which allowed reliable distinction between oncocytic and mitochondrion-rich lesions. Clinically, mitochondrial increase in non-oncocytic lesions was associated with neoplasia, malignancy and higher cancer recurrence rates. Similar correlation, albeit less pronounced, was observed within the oncocytic tumour group. By contrast, oncocytic change per se was not associated with neoplasia, malignancy or cancer aggressiveness., Conclusions: True oncocytic neoplasms can be distinguished from mitochondrion-rich non-oncocytic tumours based on aberrant distribution of all major cell organelles. This distinction has immediate clinical relevance and should be implemented in practice.

Background: Oncocytes of the thyroid gland (Hürthle cells) are found in tumors and autoimmune diseases. They have a unique appearance characterized by abundant granular eosinophilic cytoplasm and hyperchromatic nucleus. Their pathogenesis has remained, thus far, unknown., Methodology/principal Findings: Using transgenic mice chronically expressing IFNgamma in thyroid gland, we showed changes in the thyroid follicular epithelium reminiscent of the human oncocyte. Transcriptome analysis comparing transgenic to wild type thyrocytes revealed increased levels of immunoproteasome subunits like LMP2 in transgenics, suggesting an important role of the immunoproteasome in oncocyte pathogenesis. Pharmacologic blockade of the proteasome, in fact, ameliorated the oncocytic phenotype. Genetic deletion of LMP2 subunit prevented the development of the oncocytic phenotype and primary hypothyroidism. LMP2 was also found expressed in oncocytes from patients with Hashimoto thyroiditis and Hürthle cell tumors., Conclusions/significance: In summary, we report that oncocytes are the result of an increased immunoproteasome expression secondary to a chronic inflammatory milieu, and suggest LMP2 as a novel therapeutic target for the treatment of oncocytic lesions and autoimmune hypothyroidism.

Molecular imaging of tumor antisense gene techniques have been applied to the study of magnetic resonance (MR) gene imaging associated with malignant tumors. In this study, we designed, synthesized, and tested a novel molecular probe, in which the antisense oligodeoxynucleotide (ASODN) was labeled with superparamagnetic iron oxide (SPIO), and its efficiency was examined by in vitro MR imaging after SK-Br-3 mammary carcinoma cell lines (oncocytes) transfection. The SPIO-labeled ASODN probe was prepared through SPIO conjugated to ASODN using a chemical cross linking method. Its morphology and size were detected by atomic force microscope, size distribution were detected by laser granulometer, the conjugating rate and biological activity were determined by high performance liquid chromatography, and the stability was determined by polyacrylamide gel electrophoresis. After that, the probes were transfected into the SK-Br-3 oncocytes, cellular iron uptake was analyzed qualitatively at light and electron microscopy and was quantified at atomic absorption spectrometry, and the signal change of the transfected cells was observed and measured using MR imaging. The morphology of the SPIO-labeled ASODN probe was mostly spherical with well-distributed scattering, and the diameters were between 25 and 40 nm (95%) by atomic force microscope and laser granulometer, the conjugating rate of the probe was 99%. Moreover, this probe kept its activity under physiological conditions and could conjugate with antisense oligodeoxynucleotide. In addition, light microscopy revealed an intracellular uptake of iron oxides in the cytosol and electron microscopic studies revealed a lysosomal deposition of iron oxides in the transfected SK-Br-3 oncocytes by antisense probes, some of them gathered stacks, and the iron content of the group of transfected SK-Br-3 oncocytes by antisense probe is significantly higher (18.37 +/- 0.42 pg) than other contrast groups, the MR imaging showed that transfected SK-Br-3 oncocytes by antisense probe had the lowest signal of all. The SPIO-labeled ASODN probe shows unique features including well-distributed spherical morphology, high conjugating rate and loading efficiency, and the signal intensity of SPIO-labeled ASODN-transfected SK-Br-3 oncocytes is reduced in MR imaging. These results indicate that the SPIO-labeled ASODN probe is potentially useful as a MR targeting contrast enhancing agent to specifically diagnose tumors which had over-expression of the c-erbB2 oncogene at an early stage.

Oncocytic rectal carcinomas are rare and have only been documented sporadically. Oncocytes are encountered in 2 distinct settings: after preoperative chemoradiation (commoner) and without antecedent chemoradiation (uncommon). The aim of this study was to ascertain the incidence and clinicopathologic features of rectal cancers with a significant (>25%) component of oncocytes in cases not receiving chemoradiation. Of 72 cases encountered over the study period, 8 fulfilled the criteria as oncocytes. These tumors, except for the cellular component of oncocytes, were similar to conventional adenocarcinomas pathologically and immunophenotypically. Cells with eosinophilic cytoplasm are commonly seen in rectal adenocarcinomas, and they should be separated from oncocytic examples. True oncocytes may be seen in conventional adenocarcinomas as individual cells or glands, especially at the infiltrating edge of the tumor. All 8 cases appeared to have behaved aggressively with rapid local and/or distant spread over a short duration.

Background: The RET/PTC-RAS-BRAF cascade is associated with papillary thyroid carcinoma (PTC)., Objective: The relationship between PTC and Hashimoto's thyroiditis (HT) is still elusive. To determine whether thyrocytes showing oxyphil cell metaplasia in HT also express RET, RAS, and ERK proteins, which are associated with PTC., Design: We investigated the expression of RET, RAS, and ERK proteins in oxyphil cells in the vicinity of large lymphoid HT infiltrates and in malignant PTC cells. BRAF and N-RAS missense mutations were also examined in oxyphil cells of the HT. We used 47 PTC samples with no HT diagnosis, 28 PTC with HT, 39 HT with no PTC, and 36 HT with PTC. We also studied 75 normal portions of thyroid tissue from PTC specimens. Immunohistochemical analysis and polymerase chain reaction were used to determine activation of the RET/PTC-RAS-BRAF cascade in HT and PTC., Main Outcome: In PTC cells, HT oxyphil cells, and normal thyrocytes, the frequency of high RET expression was 23/70 (32.9%), 36/57 (63.2%), and 1/57 (1.8%) (p = 0.000); that of high nuclear localized RAS expression (nuclearRAS) was 65/71 (91.5%), 52/58 (89.7%), and 5/58 (8.6%) (p = 0.000); and that of high ERK expression was 38/70 (54.3%), 34/61 (55.7%), and 0/61 (0.0%) (p = 0.000), respectively. Of 66 HT cases studied for BRAF mutation and 57 HT cases studied for N-RAS mutation, no BRAF exon 15 or N-RAS exon 2 mutations were found in the amplified DNA extracted from oxyphil cells excised by laser capture microdissection., Conclusion: The expression of RET, nuclearRAS, and ERK proteins is greatly enhanced in PTC cells and HT oxyphil cells. Thus, the RET/PTC-RAS-BRAF cascade may be involved in the development of PTC and oxyphil cell metaplasia in HT. Our results show the possibility of a molecular link between oxyphil cell metaplasia in HT and the progression of PTC.

Oncocytic tumors are a distinctive class of proliferative lesions composed of cells with a striking degree of mitochondrial hyperplasia that are particularly frequent in the thyroid gland. To understand whether specific mitochondrial DNA (mtDNA) mutations are associated with the accumulation of mitochondria, we sequenced the entire mtDNA in 50 oncocytic lesions (45 thyroid tumors of epithelial cell derivation and 5 mitochondrion-rich breast tumors) and 52 control cases (21 nononcocytic thyroid tumors, 15 breast carcinomas, and 16 gliomas) by using recently developed technology that allows specific and reliable amplification of the whole mtDNA with quick mutation scanning. Thirteen oncocytic lesions (26%) presented disruptive mutations (nonsense or frameshift), whereas only two samples (3.8%) presented such mutations in the nononcocytic control group. In one case with multiple thyroid nodules analyzed separately, a disruptive mutation was found in the only nodule with oncocytic features. In one of the five mitochondrion-rich breast tumors, a disruptive mutation was identified. All disruptive mutations were found in complex I subunit genes, and the association between these mutations and the oncocytic phenotype was statistically significant (P=0.001). To study the pathogenicity of these mitochondrial mutations, primary cultures from oncocytic tumors and corresponding normal tissues were established. Electron microscopy and biochemical and molecular analyses showed that primary cultures derived from tumors bearing disruptive mutations failed to maintain the mutations and the oncocytic phenotype. We conclude that disruptive mutations in complex I subunits are markers of thyroid oncocytic tumors.

Objective: To investigate whether the presence of macrophages and Hürthle cells (HC) in benign thyroid lesions could explain the false-positive expression of galectin-3 and CD44v6 detected by reverse transcriptase-polymerase chain reaction (RT-PCR)., Methods: For galectin-3 and CD44v6, RT-PCR was performed on RNA isolated from aspirates obtained by ultrasound guided fine needle aspiration cytology (FNAC) from 123 patients with benign thyroid lesions. The results of RT-PCR analysis were evaluated against the definitive FNAC diagnosis., Results: Galectin-3 expression was found in 29% follicular adenoma (FA), 26% Hashimoto thyroiditis (HT), and in 24% nodular goitre (NG). We found a statistically significant relationship between the presence of macrophages and galectin-3 positivity in NG and HT samples (P < 0.0001 and P = 0.0087 respectively). We found a statistically significant (P = 0.0219) relationship between the presence of HC and galectin-3 positivity in HT and a tendency of such a relationship (P = 0.0838) in NG. CD44v6 expression was found in 29% FA, 33% HT and in 18% NG. We found a statistically significant relationship between the presence of HC and positive expression of CD44v6 in NG (P = 0.0003) and a strong tendency of such a relationship in HT (P = 0.0571). We did not find a statistically significant relationship between the presence of macrophages and CD44v6 positivity. In FA, we did not find a statistically significant relationship between the presence of macrophages or HC and galectin-3 or CD44v6 positivity., Conclusion: Our results suggest that the presence of macrophages and/or HC may explain the positive expression of galectin-3 and CD44v6 detected by RT-PCR in HT and NG cytological samples.

Unlabelled: In addition to tumor size, it has been suggested that P-glycoprotein (P-gp) expression and/or oxyphilic cell content in parathyroid adenomas has an important influence on the results of technetium 99m methoxyisobutylisonitrile (Tc-99m MIBI) parathyroid imaging., Aim: In this study, we compared the results of MIBI parathyroid imaging and immunohistochemical analysis (IHA) of P-gp expression, oxyphilic cell content, and tumoral tissue volume in parathyroid adenomas. We also evaluated the relationship between MIBI and ultrasound (US) results, operation findings, serum biochemical values., Materials and Methods: Forty (40) patients (36 female and 4 male; mean age, 53.2 +/- 8.16 years) with hyperparathyroidism who had undergone surgery were included in this study. Preoperatively, "double phase" parathyroid scintigraphy with Tc-99m MIBI (including imaging of the neck and mediastinum) was performed in all patients. Thirty-two (32) of the patients had also neck US. Serum parathormon (PTH), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) levels were measured preoperatively. In resected parathyroid tissues, P-gp expression and percentage of oxyphilic cell content were analyzed with IHA in 34 patients., Results: Three (3) of the resected parathyroid tissues were hyperplastic parathyroid tissue, whereas 31 of the tissues were parathyroid adenoma (mean volume, 1.99 +/- 1.93 mL). In Tc-99m MIBI parathyroid scintigraphy, 70% of the parathyroid adenoma/hyperplastic parathyroid tissue was detected in correct localization; at US, this rate was 46.8%. According to the resected parathyroid tissue localization at surgery, sensitivity, accuracy, positive predictive value, and prevalence in scintigraphy were 82.3%, 70%, 82.3%, and 85%, respectively. Those were 60%, 46.8%, 68.2%, and 78.1% for US, respectively. No significant correlation and no concordance was found between MIBI and US results (kappa, -0.103, r = -0.11; p: 0.53). Interestingly, significant correlation was found between tumoral volume and ALP level (r = 0.42; p = 0.010) and between PTH and ALP levels (r = 0.72; p < 0.001). Significant correlation was also found between patient age and tumoral volume (r =-0.37; p = 0.02) and between PTH and serum Ca levels (r = 0.32; p = 0.04). In 23 of 34 patients in whom histopathological examination was done MIBI was positive and in 13 of these patients (56.5%), P-gp expression was positive. When the histopathological results and MIBI results were compared, there was no significant correlation and concordance between P-gp expression (kappa = 0.09, r = 0.10; p = 0.54), oxyphilic cell content (r = -0.17; p = 0.33), and tumoral tissue volume (r = -0.14; p = 0.38). In 12 of 19 patients (63%) who had parathyroid tissue < 1 mL and in 15 of 24 patients (62.5%) who had oxyphilic cell content < 10%, lesions were also detected correctly with MIBI scintigraphy., Conclusions: Present study results suggest that MIBI scintigraphy was clearly superior to US as a diagnostic tool. However, P-gp expression, oxyphilic cell content, and tumoral volume may have not a main effect on MIBI parathyroid scintigraphy results in parathyroid adenoma.

The epitope H contains an O-linked N-acetylglucosamine (O-GlcNAc) residue in a specific conformation and/or environment recognized by monoclonal antibody H (mAbH). We have previously shown that the epitope H is present in more than one polypeptide and in various types of normal and pathological cells. In the present study, we focused on mitochondria-rich normal, metaplastic, and neoplastic cells, prompted by our recent immuno-electron microscopy findings that mAbH clearly stains the mitochondria of breast epithelial cells in infiltrating ductal breast carcinomas and fibroadenomas. The indirect immunoperoxidase method was applied using the mAbH to investigate the distribution of the epitope H in mitochondria-rich normal cells and in metaplastic and neoplastic oncocytic cells. Immunohistochemical staining for the mAbH was observed in oxyphil cells of parathyroid glands, in striated duct cells of parotid glands, in urinary tubules of kidneys, in parietal cells of gastric body mucosa, in oxyphil cells of Hashimoto's thyroiditis, in epithelial cells of Warthin's tumors of the parotid gland, in neoplastic cells of oxyphil adenomas and carcinomas (Hürthle's tumors) of the thyroid gland, and in neoplastic cells of oncocytomas of the kidneys. The present study shows that the epitope H is strongly expressed in mitochondria-rich normal cells, as well as in metaplastic and neoplastic oncocytic cells, which are known to have cytoplasms packed with mitochondria. Since mAbH recognizes an O-GlcNAc residue, our findings indicate that O-GlcNAc-glycosylated polypeptides are present at mitochondria where the components of the respiratory chain and energy transduction are localized. These findings may be of interest for gaining insight into the histophysiology of mitochondria-rich normal cells and into the pathogenesis of oncocytic lesions, since O-GlcNAc glycosylation may modify proteins involved in oncogenesis such as tumor suppressor proteins and oncoproteins, as well as proteins with important biological functions such as cytoskeletal proteins, transcription factors, heat-shock proteins, and chromatin proteins.

Oncocytic cell tumors (OCTs) of the thyroid include oncocytic cell adenomas (OCAs) and oncocytic cell carcinomas (OCCs). Oncocytic variant of papillary carcinoma (OVPC) has also been described. These tumors may present similar diagnostic problems as their non-oncocytic counterparts, in both conventional histology and fine-needle aspiration biopsies. Several markers were shown able to distinguish benign from malignant thyroid follicular tumors, galectin-3 and HBME-1 being the most promising ones. Controversial data have been reported on their discriminatory potential in the small series of OCTs so far analyzed. We aimed to assess the role of galectin-3 and HBME-1 in a large series of 152 OCTs (including 50 OCAs, 70 OCCs and 32 OVPCs). The expression of PPARgamma protein was also evaluated. Using a biotin-free detection system, the sensitivity of galectin-3 was 95.1%, while that for HBME-1 was nearly 53%. The combination of galectin-3 and HBME-1 increased the sensitivity up to 99%. However, for both markers, the specificity was 88%, lower than that reported for non-oncocytic follicular tumors. PPARgamma protein overexpression was absent in all OCAs tested and present in only 10% of OCCs, confirming previous reports on the low prevalence of PAX8-PPARgamma translocations in OCT and ruling out its role as a potential diagnostic marker of malignancy.

Recently, it was reported that RON proto-oncogene, encoding a receptor tyrosine kinase, was strongly expressed in renal oncocytomas but not in any renal cell carcinomas, including 5 chromophobe renal cell carcinomas, which morphologically resemble oncocytomas. To determine its diagnostic value, we studied Ron protein expression by immunohistochemistry in a larger number of renal cell neoplasms with emphasis on chromophobe renal cell carcinomas. Tissue microarrays containing 141 renal cell neoplasms, including 55 oncocytomas and 52 chromophobe renal cell carcinomas, were constructed. In addition, conventional sections from 15 cases of oncocytoma and 5 cases of chromophobe renal cell carcinoma were analyzed. Immunohistochemistry was carried out with a monoclonal mouse anti-human Ron-alpha antibody. Staining intensity was scored on a 0 to 3 scale. Ninety-nine percent of oncocytomas (69 of 70) and 96% of chromophobe renal cell carcinomas (55 of 57) showed moderate to strong, diffuse cytoplasmic Ron immunoreactivity with intensities > or =2, while only 17% of other renal cell carcinoma subtypes stained with intensities > or =2. Our study indicates that Ron immunostaining cannot be used to distinguish oncocytoma from chromophobe renal cell carcinoma.

Ectopic adrenal cortical neoplasms are extremely rare, and only a few have involved the CNS. We report the first case of an intramedullary oncocytic adrenal cortical neoplasm of the spinal cord with immunohistochemical (IMHC) confirmation. A 27-year-old man presented with progressive lower extremity weakness, spastic paraparesis, decreased reflexes, and hypoesthesia below T10. A spinal myelogram showed cauda equina blockade and obliteration of sacral nerve roots. This prompted emergent surgical intervention. A well-circumscribed, approximately 3 x 2 cm, light brown to tan, intramedullary tumor was identified at the level of the conus medullaris. Histologically, the tumor showed sheets and nests of plump, cytologically bland polygonal cells with abundant eosinophilic cytoplasm. A single mitosis, but no necrosis, was identified. By IMHC, the cells were positive for inhibin, melan-A, and synaptophysin, and negative for GFAP, EMA, cytokeratins, S-100, HMB-45, and chromogranin. Electron microscopy study performed from paraffin-embedded tissues demonstrated abundant mitochondria, and lipid vacuoles. This case confirms the occurrence of adrenal cortical neoplasms in the CNS and is the first report of an intradural, intramedullary adrenal cortical adenoma of the spinal cord, and the first to occur in a male. This tumor should be considered in the differential diagnosis of tumors of the CNS.

The overexpression of c-Kit in chromophobe renal cell carcinoma (ChRCC) has been described by comparative gene expression analyses and has been proposed as a possible specific hallmark of this neoplasm. The aim of our study was to establish its immunohistochemical expression in a large series of ChRCC and to compare it with other renal neoplasms. In our study, immunohistochemical characterization of KIT was performed in 87 renal neoplasms including 25 cases of ChRCC, 13 cases of renal oncocytoma, and 39 renal cell carcinomas (21 cases of conventional RCC [CRCC], 8 cases of CRCC with granular cell differentiation, and 10 cases of papillary RCC [PRCC]). Eighty-eight percent ChRCC and 71% oncocytomas showed immunohistochemical expression of KIT, while the other types of RCC studied were all negative. The meaning of immunohistochemical expression of KIT in ChRCC and oncocytomas is still unknown, but its immunohistochemical staining appears to be useful in distinguishing ChRCC from PRCC, CRCC, and its granular cell variant. Moreover, our findings support current models that consider that there is a histopathogenic relationship between oncocytoma and ChRCC. Finally, it should be determined whether KIT plays a role in the tumorigenesis of ChRCC and oncocytoma and whether targeted therapy with STI-571, an inhibitor of KIT, could be effective in exceptional cases of ChRCC with metastatic extension or recurrence.