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The present study describes the morphological and immunohistochemical characteristics of a case of diffuse seminoma in a 16-year-old male mixed-breed horse. According to the owner, the animal's left testicle had been gradually increasing in size over a period of 2 months. On palpation, the testicle had a firm consistency, with no sensitivity to digital pressure, was adhered to the scrotum and measuring 16 cm × 8 cm. In the ultrasound examination, it presented a heterogeneous texture and areas of hypoechogenic echogenicity without visualization of the mediastinum. Therefore, the bilateral orchiectomy was performed. After the surgical procedure, it was found that the affected testicle presented a firm mass measuring 9 cm × 7 cm × 3.5 cm. Histologically, a multilobulated, non-encapsulated and invasive tumour mass was found, which replaced the seminiferous tubules, consisting of polygonal cells arranged in a mantle that varied from cohesive to loosely cohesive, supported by a scarce fibrous stroma. In the immunohistochemical examination, the neoplastic cells showed positive immunolabelling for OCT4 and C-KIT. In this report, the physical examination combined with the ultrasonographic examination were fundamental to the therapeutic management of the case, and the final diagnosis was made after histopathological and immunohistochemical tests., (© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)

Mast cells (MCs) in rat airways have been classified into two subtypes: epithelial MCs and connective tissue MCs (CTMCs). However, the immunohistochemical characteristics, cellular morphology, and distribution of epithelial MCs in the upper airways remain unclear. The present study investigated the morphological characteristics and distribution of epithelial MCs using 5-hydroxytryptamine (5-HT) and other immunohistochemical markers in sectioned or whole-mount preparations of the rat larynx and trachea. A double immunofluorescence analysis revealed the colocalization of 5-HT immunoreactivity with c-kit, a stem cell factor receptor commonly used as a MC marker, in both epithelial MCs and CTMCs. Dopa decarboxylase, an enzyme involved in 5-HT synthesis, was detected in both subtypes, suggesting their ability to synthesize and release 5-HT. Tryptase and histidine decarboxylase (a biosynthetic enzyme of histamine), which are well-known mediators of MCs, were exclusive to CTMCs. Epithelial MCs were pleomorphic with long cytoplasmic processes, whereas CTMCs were round and lacked cytoplasmic processes. The density of epithelial MCs was significantly higher in the glottis and cranial part of the trachea than in the epiglottis and other parts of the trachea. The present results showed that the morphology and immunohistochemical characteristics of epithelial MCs were different from those of CTMCs in the rat larynx and trachea, and variform epithelial MCs were predominantly located at the entrance of the upper airways. Epithelial MCs may release 5-HT to regulate innate immune responses by modulating epithelial cell functions at the entrance gate of the upper airways., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Neuroproliferative vestibulodynia (NPV), a provoked genital pain characterized by severe allodynia and hyperalgesia, is confirmed in excised vestibular tissue by immunohistochemical staining (>8 CD117-positive immunostained cells/100× microscopic field) rather than by hematoxylin and eosin staining., Aim: In this study we sought to assess immunostaining of tissue samples obtained during vestibulectomy surgery and to correlate results with patient outcomes., Methods: Patients (n = 65) meeting criteria for NPV who underwent vestibulectomy during the period from June 2019 through December 2022 formed the study cohort. We performed assessment of pathology of vestibular tissues by use of immunohistochemical staining, including quantitation of mast cells by CD117 (mast cell marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments., Outcomes: Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement., Results: All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the marker) and nerve fibers by protein gene product (PGP) 9.5 (neuronal marker). We analyzed 725 photomicrographs of immunostained tissue sections (100× and 200×) by manual counting and computer-assisted histometry and correlated these data to clinical assessments., Outcomes: Outcomes included density of CD117 and PGP9.5 immunostaining in the 1:00-11:00 o'clock and 12:00 o'clock vestibular regions, and patient-reported outcomes assessing sexual function, pain, distress, and symptom improvement., Results: All 65 NPV patients (median age 26 years), 45 with lifelong and 20 with acquired NPV, had severe pain documented by PROs and vulvoscopy and had >8 CD117-immunopositive cells/100× microscopic field. Median cell count values were similar in the 1:00-11:00 o'clock and 12:00 vestibular regions (28.5 and 29.5/100× field, respectively). Likewise, the median area of CD117 immunostaining was similar in both regions (0.69% and 0.73%). The median area of PGP9.5 immunostaining was 0.47% and 0.31% in these same regions. Pain scores determined with cotton-tipped swab testing were nominally higher in lifelong vs acquired NPV patients, reaching statistical significance in the 1:00-11:00 o'clock region (P < .001). The median score for the McGill Pain Questionnaire affective subscale dimension was also significantly higher in lifelong vs acquired NPV patients (P = .011). No correlations were observed between hematoxylin and eosin results and density of mast cells or neuronal markers. Of note, 63% of the patient cohort reported having additional conditions associated with aberrant mast cell activity., Clinical Implications: The pathology of NPV is primarily localized to the vestibular epithelial basement membrane and subepithelial stroma with no visible vulvoscopic findings, making clinical diagnosis challenging., Strengths and Limitations: Strengths of this study include the large number of tissues examined with what is to our knowledge the first-ever assessment of the 12:00 vestibule. Major limitations are specimens from a single timepoint within the disease state and lack of control tissues., Conclusions: Performing immunohistochemical staining of excised vestibular tissue with CD117 and PGP9.5 led to histometric confirmation of NPV, indications that NPV is a field disease involving all vestibular regions, validation for patients whose pain had been ignored and who had experienced negative psychosocial impact, and appreciation that such staining can advance knowledge., (© The Author(s) 2024. Published by Oxford University Press on behalf of The International Society of Sexual Medicine.)

Abstract: Mastocytosis is a condition characterized by accumulation of clonal mast cells (MCs) that often involves the skin. Pathologists are often challenged with skin biopsies with a question of cutaneous lesions of mastocytosis (CLM) including cutaneous mastocytosis, mastocytosis in the skin, or systemic mastocytosis. The histopathological criteria for CLM remain poorly defined due to heterogeneity of the published literature and the lack of comparative prospective studies. MC count is greatly influenced by detection and counting techniques, criteria for viable MCs used, anatomical location biopsied, and the dermal level that is analyzed. Although MC numbers in CLM can be significantly higher compared with healthy controls and a patient with other inflammatory skin diseases, in some instances, considerable overlap exists. Based on the largest studies published, it is suggested that a number of MCs between 75 and 250 MCs/mm 2 are a range in which CLM should be considered and, above 250 MC/mm 2 , a diagnosis of CLM can be made. A recent study showed a high specificity of >95% of a MC count >139 MC/mm 2 compared with patients with other inflammatory skin diseases. Noteworthy, the total number and percentage of MCs is significantly higher in children compared with adults, particularly in polymorphic maculopapular cutaneous mastocytosis. In difficult cases, ancillary techniques such as D816V mutation analysis on formalin-fixed paraffin-embedded tissue have a high sensitivity and specificity. There is no enough evidence that immunohistochemistry of CD25, CD2, or CD30 has any additional value in the diagnosis, subtyping, or clinical course of mastocytosis., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The huge number of detected somatic KIT mutations highlights the necessity of in silico analyses that are almost absent in the relevant medical literature. The aim of this study is to report the mutation spectrum analysis of exon 11 encoding the juxtamembrane (JM) domain of the KIT gene in a group of Syrian GIST patients., Methods: Forty-eight formalin-fixed paraffin-embedded GIST tissue samples, collected between 2006 and 2016, were retrieved from the pathological archives and analyzed for KIT exon 11 mutations by DNA sequencing. Structural/functional impact of detected variants was predicted using several bioinformatic tools., Results: Twenty-one different variants have been detected in intron 10, exon 11, and intron 11 of the KIT gene, eight of which were novel changes. Mutations in exon 11 of the KIT gene were detected in 28 of 48 (58.3%) GIST patients and predicted to be pathogenic and cancer promoting. Specifically, age above 60 was very significantly associated with the negative selection of deletion mutations (p = .007), a phenomenon that points to deletion severity., Conclusions: Six bioinformatic tools have proved efficient in predicting the impact of detected KIT variations in view of published structural, experimental, and clinical findings., (© 2023. Egyptian National Cancer Institute.)

Type III receptor tyrosine kinase, e.g., PDGFR, are associated with various autoimmune diseases. To show the status of PDGFR and c-KIT targets, we performed the US patent analysis. The present study showed that the R&D of c-KIT target was much earlier than the R&D of PDGFR targets. Currently, the PDGFR-based target demonstrates more applications in the development of biological therapy. Our findings indicated that some inhibitors of c-KIT target contained sulfur elements or 1,3-diazine rings. The c-KIT target has more competitive edges for chemical drug discovery than the PDGFR target. c-KIT and PDGFR targets are currently preferable for drug discovery in autoimmune diseases. This study was the first to show R&D differentiation between PDGFR and c-KIT targets in drug development.

Systemic mastocytosis (SM) is a myeloid neoplasm characterized by abnormal growth and accumulation of neoplastic mast cells in at least one extracutaneous site. Clinical presentation and course are variable, most patients are developing an indolent disease and some, an aggressive/leukemic form. Because of its rarity, most physicians are unfamiliar with this disease and do not readily diagnose it. In the present retrospective study, the authors describe 12 patients diagnosed with mast cell neoplasm. Cases were selected from three institutions from Campinas and São Paulo City, Brazil. Morphological features and diagnostic pitfalls are emphasized. Patients' age ranged from 15 to 81 years (mean 51.6 years). Male and female were affected similarly (1:1). Ten patients were classified as aggressive SM, one patient as SM with an associated acute promyelocytic leukemia with t(15;17), and one patient with mast cell sarcoma. The most common clinical findings included anemia (9 patients), thrombocytopenia (3 patients), and skin lesions (3 patients). Bone marrow was involved in 11 patients at diagnosis, followed by skin (5 patients). Five morphological patterns were present: mast cell aggregates (5), plasmacytoid (4), monocytoid (2), spindle cell (2), and epithelioid/pleomorphic (1); two patients showed two histological patterns. In all cases, neoplastic cells were positive for CD117/C-KIT. C-KIT D816V mutation was present in four patients, C-KIT K509I in two, and del(7q22) in one; in five cases no mutational status was available. Despite limited resources, basically morphology and a restricted immunohistochemical panel, it is possible to diagnose mast cell neoplasm. Of note, the pathologist should recognize the different morphological variants of the disease and include adequate markers when requesting immunohistochemical studies., (Copyright © 2022. Published by Elsevier Inc.)

The diagnosis of myelodysplastic syndrome (MDS) relies primarily on identifying peripheral blood cytopenia and morphologic dysplasia as well as detecting cytogenetic aberrations in a subset of patients. Accumulating data points to the importance of examining certain immunophenotypic changes characteristic of MDS, most of which are tested by flow cytometry. The role of immunohistochemistry in the diagnostic workup of MDS is less known. In this study, we used immunohistochemistry to survey the expression patterns of CD177, P53, CD105 and c- kit in a cohort of MDS bone marrow specimens (n = 57) and compared the results with a control group of patients who had cytopenia for other benign conditions (n = 49). MDS cases showed significant higher rates of: CD177-loss (13/57, 23% vs 1/49, 2%; P = .0016), P53 overexpression (8/57, 14% vs none; P = .005) and the presence of clusters of CD105-positive cells (6/57, 11% vs none; P = .021). Increased c-kit-positive cells was more common in MDS patients, but not statistically significant (17/57, 30% vs 8/49, 16%; P = .102). On multivariate analysis, only loss of CD177 expression was significantly higher in MDS group (P = .014). These findings suggest that a panel of immunohistochemical stains could serve as an adjunct tool in investigating unexplained cytopenias and warrant further comparative studies with flow cytometry., (Copyright © 2021. Published by Elsevier Inc.)

Low-grade oncocytic tumor of the kidney (LOT) is characterized by cytoplasmic eosinophilia and a CK7-positive/CD117-negative immunophenotype. Morphologically, they exhibit overlapping features with oncocytoma and chromophobe renal cell carcinoma. Our aim was to obtain long-term clinical follow-up data, clinicopathological and molecular characteristics, and incidence of LOT. Tissue microarrays were constructed from 574 tumors historically diagnosed as oncocytoma and surgically treated at Mayo Clinic between 1970 and 2012, and immunostained for CK7 and CD117. An extended immunophenotype was obtained on whole slide sections, along with FISH for CCND1 rearrangement status and chromosomal microarray for copy number status. In addition, two cases were retrospectively identified in a set of tuberous sclerosis complex (TSC)-associated neoplasms and three more cases diagnosed on needle core biopsies were obtained during routine clinical practice. Twenty-four cases of LOT were identified among 574 consecutive tumors diagnosed as oncocytoma and treated with partial or radical nephrectomy, corresponding to an incidence of 4.18% of tumors historically diagnosed as oncocytomas, and 0.35% of 6944 nephrectomies performed between 1970 and 2012. Overall, 29 cases of LOT were identified in three clinical settings: sporadic, TSC-associated, and end-stage renal disease (ESRD). Multifocality was seen only in the setting of TSC and ESRD. No metastases attributable to LOT were identified (median follow-up 9.6 years). There were no recurrent arm level copy number changes detected by chromosomal microarray and all tested cases were negative for CCND1 rearrangement by FISH. LOT is an uncommon eosinophilic renal neoplasm with an indolent prognosis that constitutes ∼4% of tumors historically diagnosed as oncocytoma. The morphologic, immunophenotypic, and molecular features of this neoplasm suggest it is a distinct entity of renal neoplasia., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Children with Down syndrome have a 150-fold increased risk of developing myeloid leukemia, but the mechanism of predisposition is unclear. Because Down syndrome leukemogenesis initiates during fetal development, we characterized the cellular and developmental context of preleukemic initiation and leukemic progression using gene editing in human disomic and trisomic fetal hematopoietic cells and xenotransplantation. GATA binding protein 1 ( GATA1 ) mutations caused transient preleukemia when introduced into trisomy 21 long-term hematopoietic stem cells, where a subset of chromosome 21 microRNAs affected predisposition to preleukemia. By contrast, progression to leukemia was independent of trisomy 21 and originated in various stem and progenitor cells through additional mutations in cohesin genes. CD117 + /KIT proto-oncogene (KIT) cells mediated the propagation of preleukemia and leukemia, and KIT inhibition targeted preleukemic stem cells., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

To examine the clinicopathologic and immunohistochemical features of a group of newly defined low-grade oncocytic renal tumors (LOT) that have the "CD117 negative/cytokeratin (CK)7 positive" immunoprofile. We have queried our hospital database and found 4456 consecutive renal tumors between 2016 and 2019. Among these renal tumors, eight (8) cases meet the morphologic and immunohistochemical characterization for low-grade oncocytic renal tumor (LOT). The eight (8) patients' mean age is 56.6 years (range 39-70 years old), and the male to female ratio is 1:1. Macroscopically, these LOTs generally present with tan-brown and solid cut surfaces and demonstrate similar solid, compact nested growth pattern microscopically. Tumor cells exhibit oncocytic cytoplasm and uniformly rounded to oval nuclei. There are areas of edematous stroma containing dispersed single or small clustered tumor cells. All tumors are negative for CD117 and positive for CK7. Uniform reactivity is also found for BerEP4, cyclin D1, and SDHB. Besides, CD10, vimentin, and AMACR are either negative or only focally positive. All of the tumors are negative for CA9 and TFE. The Ki-67 index is less than 5% in the seven (7) internal cases. Seven (7) of the eight (8) patients who are available for follow-up are alive and without disease recurrence (mean follow-up period of 21.6 months, ranging from 6 to 43 months). We described a group of low-grade oncocytic renal tumors identified retrospectively in a large tertiary cancer center, which was probably the first report originated from China or even Asia in the English literature so far. These tumors demonstrated eosinophilic cytoplasm and low-grade appearing nuclei with a "CD117 negative/CK7 positive" immunoprofile. The incidence rate was about 3.7% of the oncocytic renal tumors and 0.18% of all the renal tumors that were received in our lab during the four-year period. It is necessary to separate this group of tumors by its characteristic morphologic and immunophenotypic features.

The histologic features of renal oncocytoma (RO) are similar to those for the more aggressive chromophobe renal cell carcinoma (ChRCC). To assess immunohistochemical markers of the two, the sensitivity and specificity of cytokeratin 7 (CK7) and C-kit, as well as hepatocyte nuclear factor-1β (HNF-1β), were analyzed. Typical cases of ChRCC and RO at Severance Hospital between July 2014 and July 2018 were selected retrospectively. Among 44 cases, 17 were unanimously compatible with ChRCC, 16 were RO, and 11 cases were indeterminate. Samples from all selected cases were used for immunostaining with antibodies against CK7, C-kit, HNF-1β, and CD10. Immunostaining demonstrated complete loss of HNF-1β expression in 11 out of 17 (64.7%) ChRCC cases and a partial, but significant loss in > 50% of tumor cells in the remaining 6 cases (35.3%). In contrast, HNF-1β expression was preserved in tumor cells of RO cases. Fourteen of 17 ChRCC cases (82.4%) were diffusely positive for CK7, whereas cases of RO were focal positive or negative. C-kit staining did not show a significant difference between ChRCC and RO. Two of five ChRCC cases showing diffuse immunoreactivity for CD10 had poor prognoses of local invasion, distant metastasis, or death. Loss of HNF-1β expression is a useful marker with which to diagnose ChRCC, especially in cases with confusing histologic findings or equivocal CK7 staining. Additionally, CD10 staining in high-grade ChRCC aids in diagnosis and prediction of the clinical prognosis.

In mammalian testes, undifferentiated spermatogonia (A undiff ) undergo differentiation in response to retinoic acid (RA), while their progenitor states are partially maintained by fibroblast growth factors (FGFs). Sertoli valve (SV) is a region located at the terminal end of seminiferous tubule (ST) adjacent to the rete testis (RT), where the high density of A undiff is constitutively maintained with the absence of active spermatogenesis. However, the molecular and cellular characteristics of SV epithelia still remain unclear. In this study, we first identified the region-specific AKT phosphorylation in the SV Sertoli cells and demonstrated non-cell autonomous specialization of Sertoli cells in the SV region by performing a Sertoli cell ablation/replacement experiment. The expression of Fgf9 was detected in the RT epithelia, while the exogenous administration of FGF9 caused ectopic AKT phosphorylation in the Sertoli cells of convoluted ST. Furthermore, we revealed the SV region-specific expression of Cyp26a1, which encodes an RA-degrading enzyme, and demonstrated that the increased RA levels in the SV region disrupt its pool of A undiff by inducing their differentiation. Taken together, RT-derived FGFs and low levels of RA signaling contribute to the non-cell-autonomous regionalization of the SV epithelia and its local maintenance of A undiff in the SV region.

Among pancreatic intraductal papillary neoplasms, gastric, intestinal, and pancreatobiliary intraductal papillary mucinous neoplasm (IPMN), intraductal oncocytic papillary neoplasm (IOPN), and intraductal tubulopapillary neoplasm (ITPN) have been defined, differing regarding association with invasive carcinoma and prognosis. Immunohistochemistry (IHC) can help in the distinction of these neoplasms, but a proportion is unclassifiable using recommended markers. Hence, additional markers useful for the typing of pancreatic intraductal papillary neoplasms are needed. The reported frequencies of the different types of IPMNs in surgical series vary to some extent, and such data based on Danish patients are currently lacking. Besides, the role of mismatch repair (MMR) deficiency in these neoplasms has not been fully elucidated. We aimed to evaluate the frequency of different types of pancreatic intraductal papillary neoplasms in a Danish cohort. Furthermore, we aimed to examine the utility of CD117, CK17, CK20, MUC4, and villin as markers for their distinction, in addition to the recommended markers MUC1, MUC2, MUC5AC, MUC6 and CDX2, and to evaluate the frequency of MMR deficiency. We typed 40 consecutively resected pancreatic intraductal papillary neoplasms according to the WHO criteria from 2019. IHC for CD117, CDX2, CK17, CK20, MLH1, MSH2, MSH6, MUC1 (H23), MUC1 (Ma695), MUC2, MUC4, MUC5AC, MUC6, PMS2, and villin was performed and evaluated using a five-tiered semiquantitative scale. A subset of the tumours was examined with PCR for microsatellite instability (MSI). Most tumours were intestinal (40 %) and gastric (40 %) IPMNs, followed by pancreatobiliary (17 %) IPMNs and IOPN (3 %). All cases were MMR proficient. We found a higher expression of MUC4, CK20 and villin in intestinal compared to gastric IPMNs (p < 0.01, p < 0.001 and p < 0.001). MUC4 was more strongly expressed in intestinal compared to pancreatobiliary IPMNs, while the opposite was found for CK17 (p < 0.05 and p < 0.05). IOPN showed strong CD117 expression (score 4), while all gastric IPMNs were negative and 50 % and 29 % of intestinal and pancreatobiliary IPMNs only showed weak expression (score 1). Our data suggest that CK20, MUC4 and villin may aid in the identification of intestinal IPMNs, while CK17 and CD117 may aid in the identification of pancreatobiliary IPMNs and IOPN, in some cases. However, additional studies evaluating these markers in pancreatic intraductal papillary neoplasms are needed., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Abstract: Cutaneous mastocytosis is characterized by the abnormal accumulation of mast cells in the skin. However, mast cell counting is not always easy and reproducible with classical methods. This work aims to demonstrate the reliability, usability, and virtues of a new software used on digital tablets for counting mast cells in cutaneous specific lesions of mastocytosis, to assess differences in mast cell counts between clinical subtypes of mastocytosis in the skin, and to consider the feasibility of applying a diagnostic mast cell count cutoff to urticaria pigmentosa, which is the most frequent form of cutaneous mastocytosis. Using a new digital tablet software that was accessible by multiple observers through its own wireless network and allowed high resolution of the image without data compression, we counted the number of mast cells on slides of patients and control skins immunostained for CD117. We found that our counting method was highly reproducible and that the new software allowed very quick counting. We evidenced strong differences in the mast cell count between most of the clinical subtypes of mastocytosis in the skin. However, when applied to a subset of patients with urticaria pigmentosa, a diagnostic cutoff in the mast cell count lacked sensitivity. Thus, our digital method for counting CD117-immunostained mast cells was highly accurate and was of a significant value for the diagnosis of mastocytosis in the skin. However, some subtypes with low mast cell counts will still require the application of additional diagnostic criteria., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Genetic lineage tracing is accomplished using bi-transgenic mice, where one allele is altered to express Cre recombinase, and another allele encodes a Cre-dependent genetic reporter protein. Once Cre is activated (constitutive or in response to tamoxifen), the marker gene-expressing cells become indelibly labeled by the reporter protein. Therefore, daughter cells derived from labeled cells are permanently labeled even if the marker gene that drove Cre recombinase expression is no longer expressed in these cells. This system is commonly used to label putative progenitor cells and determine the fate of their progeny. Here, we describe the use of c-kit-based genetic lineage-tracing mouse line as an example and discuss caveats for performing these types of experiments.

Mastocytosis is a rare myeloproliferative disease in which mast cells abnormally accumulate in the skin, bone marrow, intestine, liver, spleen, and lymph nodes. Characterized by uncontrolled proliferation of aberrant mast cells, the disease can present either cutaneously or systemically. Mast cells facilitate the immune response and inflammation, and mastocytosis with renal involvement has been rarely reported in adults. Here, we describe a pediatric case of renal involvement in a patient with mastocytosis. A 12-year-old female with mastocytosis was admitted for edema, foamy urine, and gross hematuria. Initial laboratory findings showed azotemia, proteinuria, and hematuria. Renal biopsy findings were compatible with diffuse proliferative glomerulonephritis (DPGN). Immunofluorescence analysis of CD117 (c-Kit) staining resulted positive for rare infiltrating cells. These findings are unusual for primary glomerulonephritis (GN), and secondary GN is typically associated with mastocytosis. According to the literature, steroid treatment can be attempted in cases with renal disease associated with systemic mastocytosis. Therefore, the patient was treated with oral prednisolone, and proteinuria and hematuria disappeared after 4 months of treatment. After 5 months, prednisolone treatment was stopped, and the skin lesion improved. The renal function 22 months after prednisolone treatment was normal. This is a unique report of mastocytosis with DPGN in a child. c-Kit staining can be helpful for diagnosis, and the response to steroid treatment is favorable. Further study about the pathological relevance between mastocytosis and GN is necessary.

Background & Aims: Some guidelines recommend starting colorectal cancer (CRC) screening before age 50 years for African Americans, but there are few data on screening uptake and yield in this population., Methods: We performed a prospective study of fecal immunochemical test (FIT) screening among African American members of the Kaiser Permanente Northern California health plan. We compared data from African American members screened when they were 45-50 years old (early screening group) in 2018 with data from previously unscreened African American, white, Hispanic, and Asian/Pacific Islander health plan members who were 51-56 years old. Screening outreach was performed with mailed FIT kits. Logistic regression models, adjusted for sex, were used to evaluate differences among groups in screening uptake, colonoscopy follow-up of abnormal test results, and test yield., Results: Among 10,232 African Americans in the early screening group who were mailed a FIT, screening was completed by 33.1%. Among the 4% with positive test results, 85.3% completed a follow-up colonoscopy: 57.8% had any adenoma, 33.6% had an advanced adenoma (adenoma with advanced histology or polyp ≥10 mm), and 2.6% were diagnosed with CRC. African Americans in the early screening group were modestly more likely to have completed screening than previously unscreened African Americans, whites, and Hispanics 51-56 years old. The groups did not differ significantly in positive results from the FIT (range, 3.8%-4.6%) and more than 74% received a follow-up colonoscopy after a positive test result. The test yields for any adenoma (range, 56.7%-70.7%), advanced adenoma (range, 20.0%-33.6%), and CRC (range, 0%-7.1%) were similar., Conclusions: Proportions of African Americans who participated in early (aged 45-50 years) FIT screening and test yield were comparable to those of previously unscreened African Americans, whites, Hispanics, and Asian/Pacific Islanders who were 51-56 years old., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Cancer stem cells (CSCs) are subpopulations of cancer cells with high self-renewal potential that are involved in tumor progression and recurrence. It has been postulated that CSCs and non-stem cancer cells are inter-convertible. However, precise mechanisms for the plasticity and stability of cancer stemness remain elusive. Here, we demonstrate that CD44-positive colorectal CSC fractions contain two types of cancer cells: "CD44-stable" cells, in which CD44 expression is stably sustained, and "CD44-trasnsient" cells, which are rapidly converted to CD44-negative cells. CD44-stable cells expressed higher levels of c-KIT tyrosine kinase than CD44-transient cells. c-KIT knockdown by siRNAs converted the CD44-positive cells to CD44-negative cells, which expressed lower levels of stem cell markers such as ASCL2 and EPCAM. In the CD44-positive cells, c-KIT phosphorylation level was very low whereas stem cell factor, a c-KIT ligand, elevated c-KIT phosphorylation without affecting stem cell marker expression. CRISPR-Cas9-mediated knockout of the c-KIT gene in CD44 stable cells attenuated the CSC properties including expression of CD44 and other stem cell markers, clonogenicity and in vivo tumorigenic potential in a mouse xenograft model. These observations suggest that the colorectal CSC fractions contain cancer cells with differential plasticity, which is determined by c-KIT., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: Stem cell factor receptor (c-kit) plays a crucial role in regulating proliferation and survival of germ cells. The aim of this study was to find the correlation between the number of c-kit positive germ cells, testicular asymmetry and histological grade in varicocele affected testis samples of adolescents., Materials and Methods: Twenty testicular biopsy samples of adolescents affected by varicocele and eight normal control testes were included. The relationship between percentage of testicular asymmetry, number of tubular c-kit positive germ cells and severity of spermatogenic failure was assessed., Results: The mean (SD; median) histological grade for spermatogenic failure in controls was 1.37(0.52; 1), while in the varicocele group, it was 2.70(1.08; 3) (P = .0052). Mean(SD; median) number c-kit positive germ cells in the control group were 20.1(2.52; 20), while in the varicocele group it was 12.35(7.16; 12.5) (P = .0059). Spearman test documented a significant positive correlation between percentage of hypotrophy and histological grade of spermatogenic failure (r = 0.5544 , 95% CI: 0.1345 to 0.8055, P = .0112) but a negative correlation with the number of c-kit positive cells (r = - 0.5871, 95% CI: - 0.8219 to -0.1817, P = .0065). Moreover, a significant negative correlation was found between grade of histological changes and number of c-kit positive germ cells (P < .0001)., Conclusion: A significant correlation between hypotrophy, histological lesions and c-kit positive germ cells exists in varicocele testes. This finding suggests a possible role for c-kit in the pathogenesis of germ cell impairment in varicocele. Histological changes and lack of c-kit germ cells were also noted in testes not displaying hypotrophy. We believe that reliable markers should be found as better predictors of testicular function in adolescent with varicocele.

Mesonephric carcinoma is a rare malignancy, thought to derive from Wolffian remnants. To date, no targeted molecular therapeutic options have been identified. On the basis of limited case reports, c-KIT immunohistochemical expression has been reported in female adnexal tumors of Wolffian origin, and targeted therapy with Imatinib has been attempted with mixed success. Currently, it is unclear whether c-KIT immunohistochemical expression is seen in mesonephric carcinoma, a tumor that is thought to be related to female adnexal tumors of Wolffian origin, and how this correlates with KIT mutational status. In this study, we assessed the immunohistochemical expression of c-KIT and KIT mutational status, in a series of 13 mesonephric neoplasms (5 cervical [including 2 cervical carcinosarcomas], 3 uterine corpora, 4 ovarian, and 1 vaginal/pelvic). The intensity of staining and proportion of cells showing cytoplasmic/membranous staining for c-KIT were recorded. KIT was sequenced using a next-generation sequencing panel that targeted 120 hotspots and 17 exons in 33 known actionable cancer genes. This panel included KIT exons 9, 11, and 13, and 6 hotspots (T670, D816, D820, N822, Y823, A829). Although c-KIT immunohistochemical expression was observed in the majority of mesonephric carcinomas (10/12 cases; 83%), no KIT mutations were detected. This cautions pathologists against the use of c-KIT immunohistochemistry as a surrogate marker for KIT-activating mutations in this setting. Consistent with previous studies, the majority of mesonephric neoplasms (10/13; 77%) harbored KRAS mutations. Additional mutations were found in CTNNB1 (2/13, 15%), TP53 (2/13, 15%), and PIK3CA (1/13, 8%).

One current concept suggests that unchecked proliferation of clonally selected precursors of endothelial cells (ECs) contribute to severe pulmonary arterial hypertension (PAH). We hypothesized that clonally selected ECs expressing the progenitor marker CD117 promote severe occlusive pulmonary hypertension (PH). The remodelled pulmonary arteries of PAH patients harboured CD117 + ECs. Rat lung CD117 + ECs underwent four generations of clonal expansion to enrich hyperproliferative ECs. The resulting clonally enriched ECs behaved like ECs, as measured by in vitro and in vivo angiogenesis assays. The same primitive ECs showed a limited ability for mesenchymal lineage differentiation. Endothelial differentiation and function were enhanced by blocking TGF-β signalling, promoting bone morphogenic protein (BMP) signalling. The transplantation of the EC clones caused arterio-occlusive PH in rats exposed to chronic hypoxia. These EC clones engrafted in the pulmonary arteries. Yet cessation of chronic hypoxia promoted lung cell apoptosis and resolution of vascular lesions. In conclusion, this is to the best of our knowledge, the first report that clonally enriched primitive ECs promote occlusive pulmonary arteriopathy and severe PH. These primitive EC clones further give rise to cells of endothelial and mesenchymal lineage as directed by BMP and TGF-β signaling.

Objective: To analyze acute complications of stromal gastrointestinal tumors and determine diagnosis and optimal treatment of these patients., Material and Methods: There were 33 patients with acute complications of GIST aged 40-74 years., Results: Acute complications were presented by gastrointestinal and (or) intratumoral (interstitial) bleeding (n=31). Hemorrhage was combined with stomach perforation in 1 case, intussusception and obstruction of the duodenum in 1 patient, small bowel obstruction in 2 patients. All findings were confirmed by the marker CD 117 (+). One patient died in long-term period after R0-resection and chemotherapy. Targeted therapy was used in 2 patients., Conclusion: Clinical examples indicate the progress in diagnosis and treatment of GIST due to development of instrumental imaging techniques, histological and histochemical verification of the process.

Melanoma is widely known as the most lethal skin cancer. Specific tumor-related mortality can be significantly reduced if diagnosis and treatment are properly performed during initial phases of the disease. The current search for biomarkers in early-stage melanomas is a high-priority challenge for physicians and researchers. We aimed to assess the immunoexpression of BRAFV600E and KIT in a case series consisting of 44 early-stage melanomas. Formalin-fixed paraffin-embedded samples were systematically evaluated using a semi-quantitative method based on scores of percentage and intensity for immunostained tumor cells. We observed significant concordance between BRAFV600E and KIT immunoexpression in thin invasive melanomas. Our findings corroborate previous evidence showing abnormal expression of proteins associated with MAPK intracellular signaling pathway in early-stage melanomas.

Background: There is a morphological overlap among renal epithelial tumors, particularly chromophobe renal cell carcinoma (CHRCC), clear cell renal cell carcinoma (CCRCC), renal oncocytoma (RO), and papillary renal cell carcinoma (PRCC). Discriminating between these tumors is important but sometimes challenging. This study is aimed at evaluating the clinical usefulness of the combined immunochemistry for the "three 7" markers (CK7, CD117, and Claudin-7) to distinguish chromophobe renal cell carcinoma from these mimics., Methods: Immunochemical staining for CK7, CD117, and Claudin-7 was performed in 68 CHRCCs, 199 CCRCCs, 32 ROs, and 30 PRCCs. Fluorescence in situ hybridization (FISH) was performed in some cases to exclude CCRCC and PRCC. The sensitivity (SE) and specificity (SP) for CHRCC as well as the immunoreactivity of each marker and their combinations were statistically evaluated., Results: High positive rates for CK7 (94%), CD117 (87%), Claudin-7 (94%), and their combinations (CK7+CD117, 79%; CK7+Claudin-7, 88%; CD117+Claudin-7, 82%; CK7+CD117+Claudin-7, 76%) were observed in CHRCC compared to those in CCRCC, RO, and PRCC, with increasingly higher SP when combinations of the "three 7" markers were applied (CK7, 0.80; CD117, 0.82; Claudin-7, 0.78; CK7+CD117, 0.95; CK7+Claudin-7, 0.97; CD117+Claudin-7, 0.97; CK7+CD117+Claudin-7, 1)., Conclusion: CK7, CD117, and Claudin-7 are frequently expressed in CHRCC with high specificity. We recommend the routine use of these 3 markers as a routine panel when making a differential diagnosis of CHRCC and excluding other mimics., Competing Interests: The authors declare that they have no significant relationship with or financial interest in any commercial companies with regard to this article., (Copyright © 2019 Jun Zhou et al.)

The data of literature are discordant about the role of mast cells in different types of neoplasms. In this paper the authors propose the hypothesis that tumor-associated mast cells may switch to different polarization states, conditioning the immunogenic capacities of the different neoplasms. Anti-inflammatory polarized mast cells should express cytokines such as interleukin-10 (IL-10) and then mast cells number should be inversely related to the intensity of inflammatory infiltrate. On the contrary, when mast cells do not express anti-inflammatory cytokines their number should be directly related to the intensity of the inflammatory infiltrate. In this paper we briefly argue around feasible approaches, based on the retrospective studies of tumor tissue samples from neoplasms considered "immunologically hot" and neoplasms considered "immunologically cold", through immunohistochemistry and immunofluorescence techniques (confocal microscopy). The establishment of the actual existence of a polarization interchange of mast cells, could lead to a new vision in prognostic terms, useful to contrive new approaches in immunotherapy of tumors., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

DNA amplification by PCR detects KIT exon 11 internal tandem duplications in canine mast cell tumors (MCTs). Tissue-specific inhibitors often contaminate DNA extracted from formalin-fixed, paraffin-embedded (FFPE) canine MCTs, blocking PCR amplification and, consequently, preventing mutation detection. We used a commercial kit to extract DNA from FFPE canine MCTs. Two independent PCR assays, each with one primer set, were used to amplify target genes ( HPRT and KIT ) directly after FFPE DNA extraction. PCR amplification failed with at least one primer set in 153 of 280 samples (54.6%, 95% CI: 48.8-60.5%). One or 2 DNA washing steps were required to remove PCR inhibitors in 130 of 280 (46.4%) and 23 of 280 (8.2%) of these cases, respectively. DNA concentration and quality (A 260 /A 280 and A 260 /A 230 ) either pre- or post-washing were not associated with ability of the samples to be amplified by PCR using both HPRT and KIT primer sets. Low-grade and subcutaneous MCTs were less likely to amplify directly after DNA extraction and without any washing steps compared to high-grade MCTs using KIT gene primers.

Background: Equine dysautonomia (ED) causes degeneration and loss of autonomic neurons. Approximately 50% of chronic cases recover, but it is unclear how they survive neuronal loss., Objectives: To assess lesions, autonomic neuron numbers, interstitial cells of Cajal (ICC), and neurodegeneration in recovered cases., Animals: Thirteen cases (group ED), euthanized 10.3 ± 5.2 (1-16) years from diagnosis and 6 age-matched controls (group C)., Methods: Prospective, case control; routine post mortem examination, neuron counts in peripheral and enteric ganglia and immunohistochemical assessment of neural networks (Protein gene product [PGP] 9.5), ICC (c-kit), and neurodegeneration (beta-amyloid precursor protein and ubiquitin) in intestine., Results: Postmortem findings in group ED were small intestinal dilation (4/12, 33%) and muscular hypertrophy (4/12, 33%), and gastric mucosal hypertrophy (3/11, 27%) and ulceration (4/11, 36%). Neuron density was lower in group ED (mean 39% lower for cranial cervical ganglion [P < .001], median 44% lower in celiacomesenteric ganglion [P = .01]). In intestine, neuronal depletion was worst in ileum (median 100% lower in submucosal plexus [P < .001], 91% lower in myenteric plexus [P = .004]). Group ED had less PGP 9.5 staining in ileal myenteric plexus (mean 66% lower [P = .04]) and circular muscle (median 75% lower [P = .006]). In ileum, there was less c-kit staining in myenteric plexus (median 57% lower [P = .02]) but not muscularis externa. Beta-amyloid precursor protein and ubiquitin results were not indicitive of neurodegeneration., Conclusions and Clinical Importance: Intact ICC in muscularis externa might help maintain motility after neuronal loss. Treatment supporting ICC function warrants investigation., (© 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Aim: To describe a group of distinct low-grade oncocytic renal tumours that demonstrate CD117 negative/cytokeratin (CK) 7-positive immunoprofile., Methods and Results: We identified 28 such tumours from four large renal tumour archives. We performed immunohistochemistry for: CK7, CD117, PAX8, CD10, AMACR, e-cadherin, CK20, CA9, AE1/AE3, vimentin, BerEP4, MOC31, CK5/6, p63, HMB45, melan A, CD15 and FH. In 14 cases we performed array CGH, with a successful result in nine cases. Median patient age was 66 years (range 49-78 years) with a male-to-female ratio of 1:1.8. Median tumour size was 3 cm (range 1.1-13.5 cm). All were single tumours, solid and tan-brown, without a syndromic association. On microscopy, all cases showed solid and compact nested growth. There were frequent areas of oedematous stroma with loosely arranged cells. The tumour cells had oncocytic cytoplasm with uniformly round to oval nuclei, but without significant irregularities, and showed only focal perinuclear halos. Negative CD117 and positive CK7 reactivity were present in all cases (in two cases there was focal and very weak CD117 reactivity). Uniform reactivity was found for PAX8, AE1/AE3, e-cadherin, BerEP4 and MOC31. Negative stains included CA9, CK20, vimentin, CK5/6, p63, HMB45, Melan A and CD15. CD10 and AMACR were either negative or focally positive; FH was retained. On array CGH, there were frequent deletions at 19p13.3 (seven of nine), 1p36.33 (five of nine) and 19q13.11 (four of nine); disomic status was found in two of nine cases. On follow-up (mean 31.8 months, range 1-118), all patients were alive with no disease progression., Conclusion: Low-grade oncocytic tumours that are CD117-negative/CK7-positive demonstrate consistent and readily recognisable morphology, immunoprofile and indolent behaviour., (© 2019 John Wiley & Sons Ltd.)

The autonomic innervation of the uterus is involved in multiple pathophysiological processes in both humans and animals. Pathological conditions such as adenomyosis or inflammatory pelvic disease are usually accompanied by significant alterations in uterine innervation. In the current study, we focused on autonomic innervation of uterine fibroids, the identification of recently described interstitial cells, telocytes, and the possible interplay between these structures. In this work, uterine telocytes were identified by immunopositivity for c-kit, CD34, and PDGFRα. Nerves were revealed by immunolabeling for neuronal markers: protein gene product PGP 9.5, inducible nitric oxide synthase (iNOS), choline acetyltransferase (ChAT), and tyrosine hydroxylase (TH). The gross organization of myometrial tissue has been analyzed by routine histology. The results demonstrated that the density of iNOS and ChAT-immunopositive neurons in the uterine fibroids was higher than that in the control samples. The density of telocytes in the fibrosis foci was lower than that in the normal myometrium. Our results suggest that autonomic innervation and telocytes are involved in the microenvironment imbalance characteristic of uterine leiomyoma. Since NOS-positive nerves play an important role in oxidative stress modulation, they might lead to a decrease in the number of telocytes, which are crucial components in the pathogenesis of leiomyoma formation.

Severe burns are often treated by means of autologous skin grafts, preferably following early excision of the burnt tissue. In the case of, for example, a large surface trauma, autologous skin cells can be expanded in vitro prior to transplantation to facilitate the treatment when insufficient uninjured skin is a limitation. In this study we have analyzed the impact of the enzyme (trypsin or accutase) used for cell dissociation and the incubation time on cell viability and expansion potential, as well as expression of cell surface markers indicative of stemness. Skin was collected from five individuals undergoing abdominal reduction surgery and the epidermal compartment was digested in either trypsin or accutase. Trypsin generally generated more cells than accutase and with higher viability; however, after 7 days of subsequent culture, accutase-digested samples tended to have a higher cell count than trypsin, although the differences were not significant. No significant difference was found between the enzymes in median fluorescence intensity of the analyzed stem cell markers; however, accutase digestion generated significantly higher levels of CD117- and CD49f-positive cells, but only in the 5 h digestion group. In conclusion, digestion time appeared to affect the isolated cells more than the choice of enzyme.

Background: The pathogenesis of immunological tolerance caused by avian leukosis virus subgroup J (ALV-J), an oncogenic retrovirus, is largely unknown., Results: In this study, the development, differentiation, and immunological capability of B cells and their progenitors infected with ALV-J were studied both morphologically and functionally by using a model of ALV-J congenital infection. Compared with posthatch infection, congenital infection of ALV-J resulted in severe immunological tolerance, which was identified as the absence of detectable specific antivirus antibodies. In congenitally infected chickens, immune organs, particularly the bursa of Fabricius, were poorly developed. Moreover, IgM-and IgG-positive cells and total immunoglobulin levels were significantly decreased in these chickens. Large numbers of bursa follicles with no differentiation into cortex and medulla indicated that B cell development was arrested at the early stage. Flow cytometry analysis further confirmed that ALV-J blocked the differentiation of CD117 + chB6 + B cell progenitors in the bursa of Fabricius. Furthermore, both the humoral immunity and the immunological capability of B cells and their progenitors were significantly suppressed, as assessed by (a) the antibody titres against sheep red blood cells and the Marek's disease virus attenuated serotype 1 vaccine; (b) the proliferative response of B cells against thymus-independent antigen lipopolysaccharide (LPS) in the spleen germinal centres; and (c) the capacities for proliferation, differentiation and immunoglobulin gene class-switch recombination of B cell progenitors in response to LPS and interleukin-4(IL-4) in vitro., Conclusions: These findings suggested that the anergy of B cells in congenitally infected chickens is caused by the developmental arrest and dysfunction of B cell progenitors, which is an important factor for the immunological tolerance induced by ALV-J.

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract (GIT) but have a low incidence. Arising from the interstitial cells of Cajal, GISTs occur at different sites in the GIT with stomach being the most common. They can rarely be seen at sites outside the GIT such as omentum, retroperitoneum and are called as extraintestinal GISTs (EGIST). They have a spindle or epithelioid cell morphology and show positivity by immunohistochemistry (IHC) for CD117. Our aim was to study the clinicopathological and immunohistochemical profile of our cases of EGISTs., Materials and Methods: A cross-sectional study of EGISTs received from 2010 to 2015 was done. IHC with CD117 and discovered on GIST1 (DOG1) was performed and tumors were scored based on the percentage of cells that stained positive. Thirteen abdominal non-GIST spindle cell tumors were included in the study as controls., Results: Seven cases of EGIST were included (four-omental, three-retroperitoneal). All cases stained positive for CD117 and DOG1. One case of epithelioid EGIST scored 4 + with DOG1 and 2 + with CD117. Another case with mixed morphology scored 2 + with DOG1 and 4 + with CD117. All controls were negative for both markers., Conclusion: EGISTs are one of the rare differentials for spindle cell lesions outside the GIT. Although both markers stain positive, DOG1 showed higher score with epithelioid GISTs., Competing Interests: None

Ever since the discovery of stem cells, their isolation from tissues and expansion in culture has been extensively studied due to its potential for therapeutic application. The magnetic-assisted cell sorting (MACS) method is the most widely used technique for the sorting of cells based on their cell surface markers. Though effective, the major drawbacks are high cost and the requirement for the frequent replacement of the columns. In the column-free method, the cells are sorted using the same principle of immune-magnetic isolation but does not require magnetic columns, making it cost-effective. The isolation of c-kit + stem cells from atrial explants using column-free magnet is found to be efficient and yields homogenous population of stem cells. This method saves time and labor and is economical when working with large sample sizes.

During spermatogenesis, a group of undifferentiated spermatogonia undergoes an essential transition to a differentiating stage, which involves gain of Kit receptor. In the current study, we showed that a small non-coding RNA, miRNA-26b could induce transition from Kit - to Kit + and inhibit proliferation of spermatogonia. A key transcriptional factor for undifferentiated spermatogonia, Plzf, was proven as a direct target of miR-26b. When undifferentiated spermatogonia were treated with Retinoic acid (RA), miR-26b was increased, further promoting RA-induced differentiation of spermatogonia. In addition, miR-26b could repress 5-hydroxymethylcytosine (5hmC) via repression of Tet3 in spermatogonia. These findings demonstrate that miR-26b might play a role in promoting the transition from Kit - to Kit + SSCs., (Copyright © 2018. Published by Elsevier Inc.)

Objective: To investigate the correlation between the expression of CD117, MITF, NAT10 and clinical parameters in sinonasal mucosal melanoma (SNMM). Methods: Formalin-fixed paraffin-embedded tumor specimens of 80 cases of SNMM at the Eye, Ear, Nose and Throat Hospital, Fudan University, from December 1999 to November 2013 were analyzed for CD117, MITF and NAT10 expression by immunohistochemistry. Results: There were 40 men and 40 women. The median age was 61 years, age 26 to 85 years. There was no correlation of the expression of CD117, MITF and NAT10 with the patients' age, gender, tumor site, stage, therapy method and brain metastases ( P >0.05). The expression of MITF and NAT10 was associated with lymph node metastasis and the tumors were more likely to metastasize when MITF and NAT10 were positive. However, expression of CD117 had no correlation with lymph node metastasis. Log-rank test revealed that the expression of CD117 was correlated with both three-year and five survival rate ( P =0.012, P =0.023; respectively) and patients with tumor having low expression of CD117 had the worse outcome. COX test revealed that low CD117 expression, advanced age and lymph node metastasis were independent risk factors ( P <0.05). No significant association was found between the expression of CD117, MITF and NAT10 with disease free survival ( P >0.05). Conclusions: Patients with SNMM expressing low level of CD117 have decreased survival rate. Tumors with high level of MITF and NAT10 expression are more likely to metastasize. The expression level of CD117 can be used as an important indicator for the patient survival, and the expression of MITF and NAT10 can be used as a predictor of tumor metastasis.

Low-grade eosinophilic unclassified renal cell carcinoma is a rare kidney tumor recently described, not included in the WHO classification, which is very close to oncocytoma. It is unknown to most pathologists and clinicians. From a histopathological point of view, this tumor is composed of oncocytic cells arranged in a diffuse and solid pattern, without cell nests, that makes it possible to differentiate it from oncocytoma, and expresses cytokeratin 7 (CK7) heterogeneously. We report a case with a cranial vault metastasis, and present the features to differentiate this entity from oncocytoma. Furthemore, we discuss about unclassified renal cell carcinomas with oncocytic cells., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

CD117 is a putative marker of luminal progenitor cells in the human breast. However, so far mapping the expression pattern of CD117 within the normal gland has not been reported. Here, we examined the anatomical distribution of CD117-expressing cells in lobular and ductal structures by immunohistochemistry. The presence of CD117-positive luminal cells could be divided into three distinct patterns: (1) contiguous, with coherent positive cells and rare negative cells interspaced; (2) patched, with a roughly equal frequency of positive and negative cells distributed focally; or (3) scattered, with few or no positive cells in the structure. Generally, a patched or scattered expression pattern was more frequent in lobules compared with ducts. Furthermore, an age-correlated increase in heterogeneity was observed. When comparing women below and above 21 years of age this heterogeneity was evident for both lobules and ducts. Although CD117-expression was generally segregated from luminal-lineage transcription factor GATA3-positive cells, some did co-express both markers. Finally, co-staining with Ki-67 revealed that a prominent part of cycling cells belonged to the CD117-positive population. Together these data demonstrate the presence of a CD117-expressing progenitor compartment with the capacity to replenish the luminal lineage of the breast gland.

Unraveling the fates of resident stem cells during tissue regeneration is an important objective in clinical and basic research. Genetic lineage tracing based on Cre-loxP recombination provides an effective strategy for inferring cell fate and cell conversion in vivo. However, the determination of the exact fates of resident stem cells or their derivatives in disease states and during tissue regeneration remains controversial in many fields of study, partly because of technical limitations associated with Cre-based lineage tracing, such as, for example, off-target labeling. Recently, we generated a new lineage-tracing platform we named DeaLT (dual-recombinase-activated lineage tracing) that uses the Dre-rox recombination system to enhance the precision of Cre-mediated lineage tracing. Here, we describe as an example a detailed protocol using DeaLT to trace the fate of c-Kit + cardiac stem cells and their derivatives, in the absence of any interference from nontarget cells such as cardiomyocytes, during organ homeostasis and after tissue injury. This lineage-tracing protocol can also be used to delineate the fate of resident stem cells of other organ systems, and takes ~10 months to complete, from mouse crossing to final tissue analysis.

Objectives: The aim of this study was to compare the morphology, immune phenotype, and cytokine profiles between myocardial telocytes (TCs) and bone marrow mesenchymal stem cells (MSCs), and explore the difference between those two types of interstitial cells., Methods: TCs and MSCs were cultured in vitro and cell morphology was observed with a light microscope. The expression levels of CD34, c-kit, and vimentin were detected by immunofluorescence, RT-qPCR, and Western blotting in both TCs and MSCs. The related supernatant was collected and total of 49 cytokine profiles were detected by RayBio Mice Cytokine Antibody Array. Significantly different cytokines were further confirmed by ELISA., Results: TCs have small cellular body and very long prolongations and they were CD34 + /c-kit + /vimentin + , whereas MSCs have no telopodes and they were CD34 - /c-kit - /vimentin + . Cytokine profile analysis and ELISA showed that 19 of 49 cytokines were increased dramatically in the supernatant of TCs compared with those of MSCs. Moreover, 9 of 19 cytokines were increased 2-fold at least in the supernatant of TCs compared with those of MSCs. Of 49 cytokines, 30 exhibited no significant changes in the supernatant of TCs compared with those of MSCs., Conclusions: Using various technologies, we identified that myocardial TCs and MSCs are significantly different in terms of cell structure and cytokine profiles.

The Lin - c-Kit + Sca-1 + cell population in the bone marrow (BM) serves as the direct precursor for differentiation of myeloid cells. In this study, we report that deficiency in Fpr2, a G protein-coupled chemoattractant receptor in mice, is associated with reduced BM nucleated cells, including CD31 + Ly6C + (granulocytes and monocytes), CD31 - /Ly6C int (granuloid cells), and CD31 - /Ly6C high (predominantly monocytes) cells. In particular, the number of Lin - c-Kit + Sca-1 + (LKS) cells was reduced in Fpr2 -/- mouse BM. This was supported by observations of the reduced incorporation of intraperitoneally injected bromodeoxyuridine by cells in the c-Kit + population from Fpr2 -/- mouse BM. Purified c-Kit + cells from Fpr2 -/- mice showed reduced expansion when cultured in vitro with stem cell factor (SCF). SCF/c-Kit-mediated phosphorylation of P38, STAT1, Akt (Thr-308), and Akt (Ser-473) was also significantly reduced in c-Kit + cells from Fpr2 -/- mice. Furthermore, Fpr2 agonists enhanced SCF-induced proliferation of c-Kit + cells. Colony-forming unit assays revealed that CFU-granulocyte-macrophage formation of BM cells from Fpr2 -/- mice was significantly reduced. After heat-inactivated bacterial stimulation in the airway, the expansion of c-kit + Sca-1 + cells in BM and recruitment of Ly6G + cells to the lungs and CD11b + Ly6C + TNFα + cells to the spleen of Fpr2 -/- mice was significantly reduced. These results demonstrate an important role for Fpr2 in the development of myeloid lineage precursors in mouse BM.

Objective: To investigate the clinicopathologic and differential diagnostic features of glomus tumor of the kidney. Methods: Four cases of glomus tumor of the kidney were collected from the archives of Peking University Third Hospital, the Second Hospital of Tianjin Medical University, Ningbo Yinzhou Second Hospital and Zhejiang Provincial People's Hospital between January 2012 to June 2017; the clinical and radiologic features, histomorphology, immunohistochemistry, ultrastucture and prognosis were analyzed and the relevant literature was reviewed. Results: Patients consisted of 2 men and 2 women with ages ranging from 37 years to 66 years (mean 55 years). Three patients had history of hypertensive disease (grade Ⅱ, 3 to 10 years). The tumors measured in maximum diameter from 3.0 cm to 4.0 cm (mean 3.6 cm) and showed gray-white to yellow and tan on cut surface. Macroscopical examinations showed all tumors were circumscribed but non-encapsulated. Histologically, 1 tumor presented as glomus tumor with extensive myxoid change, 1 as cellular and solid pattern glomus tumor, 1 as glomangioma with focal myopericytoma-like pattern and 1 as symplastic glomus tumor with areas resembling myopericytoma. The tumor cells in two cases showed scant cytoplasm and uniform, bland-appearing nuclei without mitoses. In one case, the tumor cells were epithelioid with abundant eosinophilic cytoplasm and relatively well-defined cell borders. There was an increased mitosis of 4/50 HPF; however, no evidence of atypical mitosis or nuclear atypia was noted. In the symplastic glomus tumor the tumor cells showed frequently nuclear pleomorphism without mitoses. By immunohistochemistry, all tumors showed strong and diffuse reactivities to at least 3 of the 4 muscle-associated markers (SMA, h-Caldesmon, MSA and Calponin), 3 tumors strongly and diffusely expressed collagen Ⅳ, 2 expressed CD34 and 1 focally expressed desmin; whereas markers including epithelial, neuroendocrine, nephrogenic, melanoma-associated, STAT6, S-100 protein, CD117 and β-catenin all were negative in all the 4 tumors. Ultrastuctural analysis was done in 2 cases and showed prominent cytoplasmic actin bundles and pericellular basement membrane, and lacking of rhomboid renin crystals in both tumors. The hypertension persisted after surgical resection for all the 3 patients with this medical history. Follow-up information (range: 6-64 months, mean: 44 months)showed that no evidence of local recurrence or distant metastasis was identified in all 4 patients. Conclusions: Glomus tumor rarely occurs in the kidney and usually has a good prognosis. Careful attention to its morphology with the judicious use of immunohistochemistry and ultrastuctural analysis can be helpful for its diagnosis and differential diagnosis.

Objective: To investigate the clinicopathologic features, immunophenotype, pathological diagnosis and treatment of malignant mixed tumor (MMT). Methods: Clinical and pathological features including immunohistochemical phenotypes were analyzed in a case of MMT accompanied with eccrine porocarcinoma (EP) involving both hands, diagnosed definitely in January 2018 along with review of relevant literature. Results: A 64-year-old man presented with multiple rash on both hands for 4 years. Three lesions of 0.5 to 2.2 cm were removed for pathological evaluation. The pathological changes on little finger of left and right hands were MMT with EP, whereas that removed from the right ring finger was EP. MMT showed infiltrative growth with vascular wall invasion and consisted of epithelial (glandular or tube differentiation) and mesenchymal components (mucinous and/or cartilage stroma). The endothelial cells showed moderate to severe cytological atypia, nuclear pleomorphism and increased mitotic activity. The glandular component had histological characteristics of syringocarcinoma with moderately atypical chondrocytes but without myoepithelium. EP was composed of basal cells with visible vacuoles in cytoplasm and the presence of tubular and squamous differentiation, along with obvious atypia. Immunohistochemically cavosurface epithelium of glandular differentiation of MMT showed positivity for CK7, EMA and CD117. Myoepithelium showed S-100, CK5/6 and p63 positivity and stromal cells were positive for S-100. Differential diagnoses included metaplastic carcinoma, malignant myoepithelioma and atypical mixed tumor of skin. Conclusions: MMT with EP is extremely rare.The diagnosis of MMT depends on the morphologic features. Immunohistochemical staining is helpful for differential diagnosis. Surgical excision with safety margins is the treatment of choice. Complementary radiotherapy and/or chemotherapy is still controversial. The clinical course of MMT is deemed unpredictable and long-term follow-up is necessary.

Objective: To study clinical and pathologic characteristics of leiomyomas of the gastrointestinal tract, and to investigate the distribution characteristics of interstitial cells of Cajal ( ICCs ) in gastrointestinal leiomyomas. Methods: One hundred and forty-seven cases of leiomyomas of gastrointestinal tract were collected at the Second Affiliated Hospital of Zhengzhou University from June 2012 to June 2017. Clinical and pathologic findings were analyzed, combined with immunohistochemistry, Alcian blue-osafranin staining and molecular study. Results: The age of patients ranged from 13-82 years with mean age of 52 years. Male to female ratio was about 1∶2. Histologically, all tumors were composed of ovoid to spindle cells arranged in short intersecting fascicles. All tumors were diffusely and strongly positive for smooth muscle antibodies, desmin and h-caldesmon by immunohistochemical staining. A prominent interspersed subpopulation of elongated/dendritic-like cells with CD117 and DOG1 positivity (accounting for 1% to 30% of all tumor cells) and negative for Alcian blue-osafranin staining was identified in all esophageal leiomyomas, 16 of 20 (80%) gastric leiomyomas and 3 of 12 small bowel leiomyomas, but none in colonic/rectal leiomyomas. Mutational analysis in 16 cases showed absence of mutation in exons 9, 11, 13 or 17 of C-KIT and exons 12 or 18 of PDGFRA. Conclusions: ICCs are identified in esophageal and gastric leiomyomas, as well as in small percentage of intestinal leiomyomas. Such findings may bring significant diagnostic pitfalls for misdiagnosis as gastrointestinal stromal tumor. Careful attention to the distribution of CD117 and DOG1 positive cells and molecular mutation analysis of C-KIT and PDGFRA may be necessary to establish the correct diagnosis.

Importance: Gastrointestinal stromal tumors (GISTs) are life-threatening when metastatic or not amenable to surgical removal. In a few patients with advanced GISTs refractory to imatinib mesylate, treatment with sunitinib malate followed by regorafenib provides tumor control; however, additional active treatments are needed for most patients., Objective: To evaluate the 6-month progression-free survival (PFS), tumor objective response, and overall survival rates in patients with GISTs treated with dasatinib., Design, Setting, and Participants: This single-arm clinical trial used a Bayesian design to enroll patients 13 years or older with measurable imatinib-refractory metastatic GISTs treated at 14 sarcoma referral centers from June 1, 2008, through December 31, 2009. A control group was not included. Patients were followed up for survival for a minimum of 5 years from date of enrollment. Tumor imaging using computed tomography or magnetic resonance imaging was performed every 8 weeks for the first 24 weeks and every 12 weeks thereafter. Tumor response was assessed by local site using the Choi criteria. Treatment was continued until tumor progression, unacceptable toxic effects after reduction in drug dose, or patient or physician decision. Archival tumor tissue was evaluated for expression of the proto-oncogene tyrosine-protein kinase Src (SRC), phosphorylated SRC (pSRC), and succinate dehydrogenase complex iron sulfur subunit B (SDHB) proteins and for mutation in the V-Kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) and platelet-derived growth factor receptor α (PDGFRA) genes. Data analysis was performed from May 19, 2017, through December 20, 2017., Interventions: Dasatinib, 70 mg orally twice daily., Main Outcomes and Measures: The primary end point was the 6-month PFS estimate using greater than 30% as evidence of an active drug and less than 10% as evidence of inactive treatment., Results: In this study, 50 patients were enrolled (median age, 60 years; age range, 19-78 years; 31 [62%] male and 19 [38%] female; 41 [82%] white), and 48 were evaluable for response. The estimated 6-month PFS rate was 29% in the overall population and 50% in a subset of 14 patients with pSRC in GISTs. Objective tumor response was observed in 25%, including 1 patient with an imatinib-resistant mutation in PDGFRA exon 18., Conclusions and Relevance: Dasatinib may have activity in a subset of patients with imatinib-resistant GISTs. Further study is needed to determine whether pSRC is a prognostic biomarker.