Search

Among intracranial cystic lesions, dermoid cysts and epidermoid cysts are relatively common benign tumors. In a small number of these tumors, it is known that squamous cell carcinomas arise in the lining epithelium of the cysts. Among tumors derived from the appendage, only one case of hidradenoma within a dermoid cyst and no cases of sebaceous tumor have been reported previously. In the present case, a protruding lesion was present in the cystic wall, and it was composed of two cell types: sebaceous cells (sebocytes) and basaloid/germinated cells, being characteristic of this tumor. It is essential to distinguish it from other sebaceous lesions such as hyperplasia, sebaceoma, sebaceous carcinoma, and basal cell carcinoma with sebaceous differentiation derived from the epidermis. The critical distinguishing points in making a differential diagnosis among these lesions are the ratio of the two cell types and the presence or absence of other components such as hair sacs, invasion or cellular atypia. Immunohistochemical examination revealed that the tumor cells were positive for the epithelial markers, such as cytokeratin (CK)14, p63, p40, high‐molecular CK, and adipophilin; these findings are peculiar to sebaceous adenoma. Although there have been several similar case reports of sebaceous tumors associated with dermmoid cysts in the ovaries, most of the intracranial lesions were squamous cell carcinomas that developed within the cysts, and there has been no precedent showing an association with a sebaceous tumor. The present report describes the first case of sebaceous adenoma that occurred in an intracranial dermoid cyst. [ABSTRACT FROM AUTHOR]

Objectives: Measurement of the macroscopic visible core (MVC) length during macroscopic on‐site quality evaluation (MOSE) may allow estimation of sample adequacy for next‐generation sequencing (NGS), and prediction of correct diagnosis in endoscopic ultrasound‐guided tissue acquisition (EUS‐TA) of pancreatic masses. Methods: This multicenter prospective study included consecutive patients who underwent EUS‐TA for pancreatic masses using a 22‐G Franseen needle. MVC length and pathological samples obtained from two needle passes were analyzed on a per‐pass basis. Outcome measures included respective correlations of MVC length with histological sample quantity and diagnostic yields. Results: The analysis included 204 passes from 102 EUS‐TAs. MVC length correlated positively with histological sample quantity (P < 0.01). On the receiver operating characteristic curve for MVC length, the cut‐off value and area under the curve for obtaining a candidate sample for NGS were 30 mm and 0.74 (95% confidence interval [CI] 0.65–0.83), respectively. On multivariate analysis, MVC length ≥30 mm was a significant factor affecting suitability for NGS (odds ratio 6.19; 95% CI 2.72–14.10). Histologic diagnostic yield correlated positively with MVC length (P = 0.01); however, there was no positive correlation between MVC length and overall (histology plus cytology) diagnostic yield. Conclusions: Measuring MVC length to predict histological sample quantity on MOSE may be of clinical significance during EUS‐TA using a 22‐G Franseen needle. It may be an effective method, particularly while submitting samples for NGS. Registration: University Hospital Medical Information Network Trials Registry (UMIN000036528). [ABSTRACT FROM AUTHOR]

Aims: This study investigated the relationship between the differentiation of tumour cells into crypts, which is determined by cell differentiation into Paneth and neuroendocrine cells, and tumour infiltration in gastric dysplasia. Methods and results: The lesions were endoscopically biopsied low‐grade dysplasia (LGD), endoscopically resected high‐grade dysplasia (HGD) or cancer with submucosal invasion. LGD (n = 32) displayed crypt differentiation across the entire width of the tumour in all cases. Crypt differentiation was identified as a characteristic of tumours with low biological malignancy. HGD (n = 40) included tumours with a mixture of areas with and without crypt differentiation (n = 25) and tumours with crypt differentiation throughout the entire width (n = 15). Of the cancers with submucosal invasion (n = 30), the morphological progression of the HGD area with crypt differentiation, the HGD area without crypt differentiation and invasive cancer without crypt differentiation was confirmed for 23 samples. In two lesions, invasive cancer without crypt differentiation developed from HGD without crypt differentiation throughout the tumour width. In five samples, well‐differentiated tubular adenocarcinoma with crypt differentiation developed from HGD with crypt differentiation and invaded with lamina propria‐like stroma. Conclusions: Loss of crypt differentiation could be an objective indicator of infiltration in the progression of HGD to invasive cancer. The invasive potential of dysplasia depends upon the presence or absence of crypt differentiation. [ABSTRACT FROM AUTHOR]

Ayu-narezushi, a traditional Japanese fermented food, comprises abundant levels of lactic acid bacteria (LAB) and free amino acids. This study aimed to examine the potential beneficial effects of ayu-narezushi and investigated whether ayu-narezushi led to improvements in the Tsumura Suzuki obese diabetes (TSOD) mice model of spontaneous metabolic syndrome because useful LAB are known as probiotics that regulate intestinal function. In the present study, the increased body weight of the TSOD mice was attenuated in those fed the ayu-narezushi-comprised chow (ayu-narezushi group) compared with those fed the normal rodent chow (control group). Serum triglyceride and cholesterol levels were significantly lower in the Ayu-narezushi group than in the control group at 24 weeks of age. Furthermore, hepatic mRNA levels of carnitine-palmitoyl transferase 1 and acyl-CoA oxidase, which related to fatty acid oxidation, were significantly increased in the ayu-narezushi group than in the control group at 24 weeks of age. In conclusion, these results suggested that continuous feeding with ayu-narezushi improved obesity and dyslipidemia in the TSOD mice and that the activation of fatty acid oxidation in the liver might contribute to these improvements. [ABSTRACT FROM AUTHOR]

Background: Skeletal muscle is mainly responsible for insulin‐stimulated glucose disposal. Dysfunction in skeletal muscle metabolism especially during obesity contributes to the insulin resistance. Astaxanthin (AX), a natural antioxidant, has been shown to ameliorate hepatic insulin resistance in obese mice. However, its effects in skeletal muscle are poorly understood. The current study aimed to investigate the molecular target of AX in ameliorating skeletal muscle insulin resistance. Methods: We fed 6‐week‐old male C57BL/6J mice with normal chow (NC) or NC supplemented with AX (NC+AX) and high‐fat‐diet (HFD) or HFD supplemented with AX for 24 weeks. We determined the effect of AX on various parameters including insulin sensitivity, glucose uptake, inflammation, kinase signaling, gene expression, and mitochondrial function in muscle. We also determined energy metabolism in intact C2C12 cells treated with AX using the Seahorse XFe96 Extracellular Flux Analyzer and assessed the effect of AX on mitochondrial oxidative phosphorylation and mitochondrial biogenesis. Results: AX‐treated HFD mice showed improved metabolic status with significant reduction in blood glucose, serum total triglycerides, and cholesterol (p< 0.05). AX‐treated HFD mice also showed improved glucose metabolism by enhancing glucose incorporation into peripheral target tissues, such as the skeletal muscle, rather than by suppressing gluconeogenesis in the liver as shown by hyperinsulinemic–euglycemic clamp study. AX activated AMPK in the skeletal muscle of the HFD mice and upregulated the expressions of transcriptional factors and coactivator, thereby inducing mitochondrial remodeling, including increased mitochondrial oxidative phosphorylation component and free fatty acid metabolism. We also assessed the effects of AX on mitochondrial biogenesis in the siRNA‐mediated AMPK‐depleted C2C12 cells and showed that the effect of AX was lost in the genetically AMPK‐depleted C2C12 cells. Collectively, AX treatment (i) significantly ameliorated insulin resistance and glucose intolerance through regulation of AMPK activation in the muscle, (ii) stimulated mitochondrial biogenesis in the muscle, (iii) enhanced exercise tolerance and exercise‐induced fatty acid metabolism, and (iv) exerted antiinflammatory effects via its antioxidant activity in adipose tissue. Conclusions: We concluded that AX treatment stimulated mitochondrial biogenesis and significantly ameliorated insulin resistance through activation of AMPK pathway in the skeletal muscle. [ABSTRACT FROM AUTHOR]

Abstract: Anti‐Ro52 autoantibodies (Ro52‐autoAbs) appear in the sera of connective tissue disease (CTD) patients with interstitial lung disease (ILD). Studies using patient sera have shown a correlation between the generation of Ro52‐autoAbs and the clinical morbidity and severity of CTD with ILD. In this study, we used a single B‐cell manipulating technology and obtained 12 different monoclonal Ro52‐autoAbs (mRo52‐autoAbs) from the selected four patients suffering from severe ILD with a high titer of Ro52‐autoAbs in their sera. Western blot analysis revealed that 11 of 12 mRo52‐autoAbs bound to the coiled‐coil domain of Ro52. Competitive ELISA demonstrated that mRo52‐autoAbs competed with each other to bind to Ro52. Epitope mapping showed that two of them specifically bound to a peptide (PEP08) in the coiled‐coil domain. We then examined the titer of Ro52‐autoAbs in the sera of 192 CTD patients and assessed the relationship between the serum levels of Ro52‐autoAbs that were reactive to PEP08 peptide and the clinical morbidity and severity of ILD. Statistical analysis revealed that the production of PEP08‐reactive Ro52‐autoAbs correlated with the morbidity and severity of ILD in CTD. Assessment of the production of PEP08‐reactive Ro52‐autoAbs in autoimmune diseases is useful for predicting the clinical morbidity of ILD. [ABSTRACT FROM AUTHOR]

ABSTRACT: Aim: Animal bile preparations harvested from bears, cattle, and pigs are composed of distinct types of bile acids. Given that several types of bile acid activate the farnesoid X receptor (FXR) or Takeda G‐protein receptor 5 (TGR5) and thereby exert anti‐inflammatory effects, we compared the effects of the three animal bile preparations on dextran sulfate sodium (DSS)‐induced colitis in mice. Methods: Bear bile (BB), cattle bile (CB), and pig bile (PB) were orally given at 100 mg/kg/day during DSS treatment for 7 days. The colitis symptoms and the histological and biochemical markers of inflammatory response in the colon tissues were assessed. Results: BB, CB, and PB similarly ameliorated the colitis symptoms in DSS‐treated mice. BB and CB but not PB attenuated inflammatory response in the colon tissues of DSS‐treated mice. The content of the bile acids agonistic to FXR and TGR5 was significantly increased by BB and CB but not by PB. Conclusion: BB, CB, and PB are indistinguishable in ameliorating colitis symptoms in DSS‐treated mice. The differences, however, in the effects of the three animal bile preparations on colon inflammation may be due to the differences in the content of anti‐inflammatory bile acids. [ABSTRACT FROM AUTHOR]

Tsumura Suzuki obese diabetes (TSOD) mice spontaneously develop obesity and type 2 diabetes with aberrant accumulation of excessive iron in the spleen. Aberrantly accumulated iron may cause oxidative stress and result in various symptoms of metabolic syndrome in the mice. We investigated iron metabolism and oxidative stress in TSOD mice. Male TSOD and control mice were killed at 2, 3, 6, and 8 months of age, and blood and tissue samples were collected. The serum levels of ferritin and oxidized low-density lipoprotein (OxLDL) were measured. Total glutathione concentrations of liver and spleen were also measured. Serum ferritin and OxLDL were higher in TSOD mice than in control mice at 2 and 6 months. In addition, the glutathione concentrations in TSOD mice were lower in the liver and higher in the spleen at 3 and 6 months than those in control mice. These results suggest that abnormal iron metabolism and imbalanced oxidative stress occurs in young and old TSOD mice. We propose herein that TSOD mice might be a unique and valuable model for investigating the role of iron metabolism in pathogenesis of metabolic syndrome. [ABSTRACT FROM AUTHOR]

Objective To investigate the reactivity of monoclonal anti-citrullinated protein antibody (ACPA) obtained from peripheral blood B cells of rheumatoid arthritis (RA) patients with human autoantigens as well as environmental proteins by determining the essential epitope for the ACPA. Methods A human monoclonal ACPA (cyclic citrullinated peptide antibody 1 [CCP-Ab1]) was obtained by screening peripheral blood lymphocytes from 31 patients with RA using a novel monoclonal antibody-secreting cell (ASC) screening system, the immunospot-array assay on a chip. The essential epitope for CCP-Ab1 was determined using epitope mapping. Then, human, microbial, and plant proteins that share the essential epitope identified were searched using BLAST. Finally, representative proteins identified by the search were produced in vitro, and their reactivity with CCP-Ab1 was examined. Results CCP-Ab1 bound CCP in a citrulline-indispensable manner. In CCP, the 6 amino acid residues required for CCP-Ab1 binding were identified. In the BLAST search, 38 human, 56 viral, 1,383 fungal, 547 bacterial, and 1,072 plant proteins were found to share the essential epitope, and CCP-Ab1 reacted with all of the recombinant citrullinated proteins tested, which included the various environmental factors, such as various plant proteins that are part of the daily diet. Conclusion Our findings demonstrate, for the first time, that a monoclonal ACPA (CCP-Ab1) derived from RA patients cross-reacts not only with various autoantigens but also with numerous plant and microbial proteins. We propose that countless environmental factors, including microbes and diet, may trigger the generation of ACPAs that then cross-react with various citrullinated human autoantigens through molecular mimicry to induce RA. [ABSTRACT FROM AUTHOR]

Objective. Patients with gastroenteropancreatic neuroendocrine carcinoma (NEC) have a poor prognosis. Platinum-based combination chemotherapy is commonly used as first-line treatment; however, the role of salvage chemotherapy remains unknown. This study aimed to analyze the efficacy and safety of amrubicin monotherapy in patients with platinum-refractory gastroenteropancreatic NEC. Methods. Among 22 patients with advanced gastroenteropancreatic NEC, 10 received amrubicin monotherapy between September 2007 and May 2014 after failure of platinum-based chemotherapy. The efficacy and toxicity of the treatment were analyzed retrospectively. Results. Eight males and two females (median age, 67 years (range, 52–78)) received platinum-based chemotherapy, including cisplatin plus irinotecan (n=7, 70%), cisplatin plus etoposide (n=2, 20%), and carboplatin plus etoposide (n=1, 10%) before amrubicin therapy. Median progression-free survival and overall survival after amrubicin therapy were 2.6 and 5.0 months, respectively. Two patients had partial response (20% response rate), and their PFS were 6.2 months and 6.3 months, respectively. Furthermore, NEC with response for amrubicin had characteristics with a high Ki-67 index and receipt of prior chemotherapy with cisplatin and irinotecan. Grade 3-4 neutropenia and anemia were observed in four and five patients, respectively. Conclusion. Amrubicin monotherapy appears to be potentially active and well-tolerated for platinum-refractory gastroenteropancreatic NEC. [ABSTRACT FROM AUTHOR]

Background and Aim: Non-alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome (MS). Monosodium glutamate (MSG)-treated ICR mice is a useful model of MS and NASH, but it shows the different patterns of steatosis from human NASH. Because inbred aged DIAR (ddY, Institute for Animal Reproduction) mice spontaneously show the similar pattern of steatosis as NASH, we analyzed their liver pathology after administering MSG. Methods: MSG-treated DIAR mice (DIAR-MSG) and untreated DIAR mice (DIARcontrols) were sacrificed and assessed histopathologically at 29, 32, 40, 48, and 54 weeks of age. The NASH activity score, body mass index, blood glucose level, and oral glucose tolerance test were also assessed. Results: The body mass index and blood glucose levels of DIAR-MSG were significantly higher than controls. The oral glucose tolerance test revealed a type 2 diabetes pattern in DIAR-MSG. The livers of DIAR-MSG mice showed macrovesicular steatosis, lobular inflammation with neutrophils, and ballooning degeneration after 29 weeks. At 54 weeks, mild fibrosis was observed in 5/6 DIAR-MSG and 2/5 DIAR-control mice. In imaging mass spectrometry analysis, cholesterol as well as triglyceride accumulated in the liver of DIAR-MSG mice. Atypical liver nodules were also observed after 32 weeks in DIARMSG, some with cellular and structural atypia mimicking human hepatocellular carcinoma. The NASH activity score of DIAR-MSG after 29 weeks was higher than that of control mice, suggesting the development of NASH. Conclusions: DIAR-MSG had NASH-like liver pathology and liver nodules typically associated with MS symptoms. DIAR-MSG provides a valuable animal model to analyze NASH pathogenesis and carcinogenesis. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the expression pattern of manganese superoxide dismutase ( MnSOD) in relation to inflammatory factors in ulcerative colitis ( UC) and characterize this enzyme as a newly identified biomarker potentially linked to disease pathogenesis of UC. MnSOD expression was analyzed immunohistochemically in 48 formalin-fixed and paraffin-embedded specimens from patients with UC who had undergone endoscopical biopsy. MnSOD expression was observed in vascular endothelium, macrophages, and polymorphonuclear leukocytes within lamina propria of inflamed mucosa. The patients who did not express MnSOD tended to have stabilization of symptoms, but accompanied with status of inflammation. The MnSOD expression pattern was strongly correlated with disease type. MnSOD was expressed in polymorphonuclear leukocytes of all disease types, but cases of chronically counting and exacerbation type had particularly high frequency of immunopositive cells. MnSOD expression in macrophages was frequently observed in cases of symptom remaining type. The cases with MnSOD expression in the vascular endothelium showed a tendency to express in relapse-remission and exacerbation of symptoms. Immunohistochemical evaluation for MnSOD expression may be useful for predicting disease severity and activity in patients with UC. [ABSTRACT FROM AUTHOR]

We report an adult case of midgut volvulus in familial visceral myopathy (FVM) that had affected family members over three generations. The patient was a Japanese woman in her fifties, who had chronic intestinal pseudo-obstruction (CIPO) since the age of about 40 years and had been treated chronically with conservative therapies. Her abdominal symptoms suddenly worsened and surgery became necessary. Surgery revealed a midgut volvulus secondary to intestinal malrotation and the twisted intestine was resected. Histology revealed diffuse damage of myocytes confined to the muscularis propria throughout the resected intestine. The myocytes were irregulary arranged, contained cytoplasmic inclusions, and had mild and focal vacuolar changes. The mucsularis propria showed hypertrophy with delicate interstitial fibrosis. A diagnosis of FVM was made on the basis of this characteristic myopathy. Intestinal malrotation is known to be a complication of CIPO in children, but is rare in adults. Although midgut volvulus appears to be extremely rare, it can occur after a relatively stable chronic phase in adult CIPO patients, who should be monitored carefully to assess the risk of such complications. [ABSTRACT FROM AUTHOR]

Stimulation of the CD155/poliovirus receptor, which localizes in the cell-matrix and at cell-cell junctions, inhibits cell adhesion and enhances cell migration. Necl-5, a mouse homolog of CD155, is implicated in the formation of adherence junctions. Recently, Necl-5 has also been found to enhance cell proliferation via the stimulation of serum and platelet-derived growth factor through the Ras-Raf-MEK-ERK signaling pathway. In our present study, we find that CD155 significantly enhances the serum-induced cell proliferation of NIH3T3 cells which have been transformed by an oncogenic Ras (V12Ras-NIH3T3), but not the parental cells. CD155 expression in V12Ras-NIH3T3 cells is also found to upregulate cyclin D2, downregulate p27 [ABSTRACT FROM AUTHOR]

Background and Aims: Although patients with early colorectal cancer invading the submucosa (CRC-sm) may be treated with endoscopic mucosal resection alone, they generally undergo additional surgery because of the risk of lymph node metastasis. The aims of the present study were to examine the roles of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in tumor vascularization and to investigate whether COX-2 and VEGF expression and tumor vascularity are useful markers for predicting lymph node metastasis in CRC-sm. Methods: Twenty-seven resected specimens of CRC-sm with lymph node dissection were examined, and expression of COX-2 and VEGF was evaluated immunohistochemically and scored. Microvessel density (MVD) in CRC-sm tissues was estimated using a Macscope system after CD34 immunostaining. The relationships among clinicopathological parameters, COX-2 and VEGF expression, and MVD in CRC-sm tissues were then analyzed. Results: Scores for COX-2, VEGF and MVD were all significantly higher in patients with CRC-sm with lymphatic invasion or lymph node metastasis. COX-2 score ( P < 0.0001) and VEGF score ( P = 0.035) were significantly correlated with MVD in CRC-sm tissues. In addition, COX-2 score was significantly correlated with VEGF score in the CRC-sm specimens examined. Conclusions: Both COX-2 and VEGF are involved in tumor vascularization in CRC-sm. COX-2 expression, VEGF expression, and MVD are possible markers for predicting lymph node metastasis in patients with CRC-sm, and use of COX-2 expression may be clinically practical. [ABSTRACT FROM AUTHOR]

Background and Aim: Recent advances in colonoscopic techniques have led to the increased detection of, and interest in, superficial type colorectal tumors, and a new category, the ‘laterally spreading tumor (LST)’, has been proposed. However, the characteristics of the genetic alterations in these LSTs have not yet been fully determined. We therefore classified LSTs as LST-granular (LST-G) or LST-non-granular (LST-NG), according to their macroscopic appearance, and examined the genetic alterations in these two tumor groups compared with those in protruded type tumors. Methods: We obtained a total of 62 colorectal tumors, including 26 protruded type, 17 LST-G and 19 LST-NG, from specimens resected surgically or endoscopically. We examined K-ras codon 12 mutations by using the polymerase chain reaction-restriction fragment length polymorphism method and by fluorescence direct sequencing. We also performed immunohistochemistry to analyze cyclooxygenase (COX)-2 and gastrin abnormalities. Results: The incidence of K-ras mutation was 50.0% in protruded type tumors, 76.5% in LST-G, and 26.3% in LST-NG. The frequencies of COX-2 overexpression were 73.1, 88.2, and 31.6%, respectively, and those of gastrin overexpression were 61.5, 82.4, and 26.3%, respectively. Therefore, LST-G is similar to protruded type tumors in that the incidence of K-ras mutation and the frequencies of COX-2 and gastrin overexpression are high. LST-NG differs from both of these tumor types in that the values of these three indicators are all low. Conclusions: These results show that LST-G and LST-NG have different genetic alterations. © 2005 Blackwell Publishing Asia Pty Ltd [ABSTRACT FROM AUTHOR]

It is still not clear which parameters are important for predicting the metastatic potential of superficial esophageal squamous cell carcinoma (SESCC). The purpose of the present paper was thus to investigate tumor cell dissociation (TCD) in SESCC as a predictive factor of lymph node metastasis. Thirty-three SESCC were classified into four groups based on the depth of tumor invasion. Carcinomas not invading as far as the muscularis mucosa were classified as group A; carcinomas invading to the muscularis mucosa or less than one-third of the upper submucosa were classified as group B; those invading to the middle layer of the submucosa were classified as group C; and those invading one-third of the lower submucosa were classified as group D. The TCD score was calculated by dividing the length of the TCD region by the maximal longitudinal length of the area of invasion into or beyond the lamina propria, and multiplying by 100. E-cadherin expression of the carcinomas was investigated in the TCD area and the successive area of mucosal invasive carcinoma (SAM). The incidence of lymph node metastasis was 0% in group A, 10% in group B, 36.4% in group C and 57.1% in group D. The mean TCD scores (±SEM) of SESCC with lymph node metastasis were higher than that without (85.3 ± 5.7, 16.3 ± 3.9, respectively; P < 0.001). In group C, the TCD score of cases with lymph node metastases was higher than in those without lymph node metastasis ( P < 0.001). E-cadherin expression was significantly reduced in the area of TCD compared with the SAM located over the TCD area ( P < 0.001). The TCD score is an important predictive marker for lymph node metastasis in SESCC. Clinical evaluation of TCD scores in endoscopic mucosal resection (EMR) specimens would enable accurate prediction of lymph node metastasis and extend the indication of EMR treatment for SESCC. [ABSTRACT FROM AUTHOR]

Imura J, Tomita S, Ono Y, Inaba F, Yamazaki T, Fukasawa I, Inaba N, Fujimori T. Endometrial adenosquamous carcinoma with osteoclast-like giant cells: immunohistochemistry and histogenesis. APMIS 2005;113:140–4.Primary extraskeletal epithelial neoplasms containing osteoclast-like giant cells (OGCs) are rare. We herein describe a case of adenosquamous carcinoma that developed in the endometrium together with non-neoplastic OGCs. The patient was a 72-year-old woman who underwent radical hysterectomy with salpingo-oophorectomy and lymph node dissection after being diagnosed with uterine cancer. Histologically, the tumor was found to be an adenosquamous carcinoma containing a large number of OGCs and mononuclear cells (MNCs) that had infiltrated into the stroma. Immunohistochemically, the OGCs and MNCs stained strongly positive for KP-1 and alpha-1-antichymotrypsin, and negative for the epithelial markers epithelial membrane antigen (EMA) and cytokeratins. These findings suggest that the OGCs and MNCs in this patient's tumor originated from monocytes/histiocytes, and most likely developed as part of the stromal reaction to the neoplasm. [ABSTRACT FROM AUTHOR]

Imura J, Ichikawa K, Takeda J, Tomita S, Yamamoto H, Nakazono M, Takimoto T, Ueda Y, Fujimori T. Multilocular cystic renal cell carcinoma: a clinicopathological, immuno- and lectin histochemical study of nine cases. APMIS 2004;112:183–91. Multilocular cystic renal cell carcinoma (MCRCC) is an uncommon variant of renal neoplasm and its histogenesis is unclear. The aim of this study was to use immuno- and lectin histochemistry to delineate histochemical patterns which might indicate the histogenetic origin of MCRCC from a particular part or parts of the nephron. We present our experience with nine cases of MCRCC. Fifteen cases of renal cell carcinoma with cystic degeneration (RCC-CD) were selected for comparison with MCRCC. We carried out clinicopathological and immunohistochemical examinations of the MCRCC cases. Clinically, the prognosis of the patients was quite good, in that all nine patients are alive and without recurrence at the time of this report. The MCRCCs reacted strongly in a higher proportion of cases with the distal nephron markers, such as peanut agglutinin (PNA, 88.9%) and MUC1–core antibody (MUC1, 100%), but none reacted preferentially with proximal nephron markers such as vimentin, Leu M1 and Lotus tetragonolobus (LTA). The RCC-CD tumours reacted with vimentin (40%), Leu M1 (66.7%) and LTA (86.7%). Except for two cases, the RCC-CD tumours did not react with PNA or MUC1 core antibody. These results illustrate the different patterns of expression of MCRCC and RCC-CD and suggest that MCRCC originates from the distal nephron. Therefore, MCRCC should be differentiated from other types of renal cell carcinoma on the basis of the histogenesis of the tumour and the clinicopathological findings. [ABSTRACT FROM AUTHOR]

We report a localized malignant mesothelioma of the epithelial type, occurring as a primary hepatic neoplasm in a 64-year-old male. He was found to have a mass located in the right lobe of the liver. Surgery was carried out with resection of the mass from the right hepatic lobe, with partial resection of the diaphragm. Grossly, an ill-defined tumor was present in the hepatic parenchyma. Histologically, the tumor displayed a predominant tubular pattern of growth with a desmoplastic stroma. The tubules were lined by a single layer of cuboidal or flattened cells with pleomorphic vesicular nuclei. A hyaluronidase-digestible, mucin-like substance was demonstrated in the lumen and tumor cytoplasm. The tumor cells were immunohistochemically positive for calretinin, HBME-1, cytokeratin, i.e. AE1/AE3 and CAM 5.2, but negative for carcinoembryonic antigen, CD 34 and Leu M1. Moreover, the tumor cells showed nuclear accumulation of the p53 oncopotein and reacted frequently with Ki-67 antibody. These findings support the concept that malignant mesothelioma of the epithelial type may occur at extrapleural sites. To the best of our knowledge, this is the first reported case of localized malignant primary mesothelioma arising in the liver. [ABSTRACT FROM AUTHOR]

Pseudomalignant erosion is a diagnostic pitfall for pathologists in the differential diagnosis of malignant neoplasms. Here, we present a challenging case of a biopsy specimen from the eroded head of a polyp at the esophagogastric junction. A malignant neoplasm could not be ruled out due to the presence of bizarre stromal cells. A second biopsy performed after the administration of a proton pump inhibitor (PPI) for 4 weeks revealed endoscopic resolution of the polyp along with the complete histological resolution of the bizarre stromal cells and led to the diagnosis of pseudomalignant erosion in a reflux gastroesophageal polyp. In conclusion, histological and endoscopic response to PPI therapy is an important clue for the correct diagnosis of reflux gastroesophageal polyps with pseudomalignant erosion. [ABSTRACT FROM AUTHOR]

We report a case of a gastrointestinal stromal tumor (GIST) of the stomach that demonstrated a stepwise progression from lowto high-grade malignancy. The patient had been followed for a small gastric submucosal tumor that had turned malignant after 8 years of indolence, manifested by tarry stools. The tumor was enucleated, and gastric GIST was diagnosed. The most significant histological finding was that the tumor comprised two clearly demarcated areas, one with less aggressive characteristics and the other with highly aggressive characteristics. The patient exhibited multiple liver metastases 24 months after surgery. Imatinib mesylate was not administered throughout the clinical course because it was not available for clinical use at that time. The patient followed an unfavorable clinical course and died of liver dysfunction 55 months after surgery. Autopsy was performed. By comparing the immunohistochemical profiles of primary and metastatic tumors, it was established that only the tumor cells with highly aggressive characteristics had metastasized. [ABSTRACT FROM AUTHOR]

We report a case of diffuse follicular center lymphoma (FCL), which is a morphological variant of follicular lymphoma, resembling multiple lymphomatous polyposis (mantle cell lymphoma of the intestine). The patient was a 48-year-old Japanese man who was found, by colonoscopy, to have numerous small polypoid lesions along the entire large intestine. Abdominal computed tomography revealed hepatosplenomegaly and enlargement of multiple mesenteric lymph nodes. Histologically, the lesion was characterized by diffuse proliferation of small- to medium-sized lymphocytes with cleaved nuclei in the mucosa and submucosa. Immunohistochemical studies showed that the tumor cells were CD20+, CD10+, BCL-2+, CD5-, surface IgM-, and cyclin D1-. Moreover, a cytogenetic study showed a translocation at (14;18)(q32;q21). Finally, this case was diagnosed as diffuse FCL, although the tumor was mimicking mantle cell lymphoma., (Copyright 2003 Wiley-Liss, Inc.)