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Clear Cells (clear + cell)
Terms modified by Clear Cells Selected AbstractsStructure of the Lining Epithelium of the Cauda Epididymis of the Golden HamsterANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009C. C. L. Beu Summary The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes (¾ of basal cytoplasm), and vacuoles and vesicles (¼ of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster. [source] Fine needle aspiration of renal cortical lesions in adultsDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2010Adebowale J. Adeniran M.D. Abstract The role of fine needle aspiration (FNA) biopsy of renal cortical lesions was controversial in the past because the result of the FNA did not affect clinical management. All renal cortical lesions, except metastasis, were subject to surgical resection. However, with the advances in neoadjuvant targeted therapies, knowledge of the renal cortical tumor histological subtype is critical for tailoring clinical trials and follow-up strategies. At present, there are clinical trials involving the use of novel kinase inhibitors for conventional (clear cell) and papillary renal cell carcinoma. We studied 143 consecutive cases of renal cortical lesions, evaluated after radical or partial nephrectomies over a 2-year period. An air-dried smear and a Thinprep® slide were prepared in all cases. The slides were Diff-Quick and Papanicolaou stained, respectively. The cytology specimens were reviewed and the results were then compared with the histologic diagnosis. Cytology was highly accurate to diagnose conventional RCC, while the accuracy for papillary RCC, chromophobe RCC, and papillary urothelial carcinoma was much lower. Our results indicate that ancillary studies might have an important role in the subclassification of renal cortical neoplasms for targeted treatment. Diagn. Cytopathol. 2010;38:710,715. © 2009 Wiley-Liss, Inc. [source] Renal cell carcinoma marker reliably discriminates central nervous system haemangioblastoma from brain metastases of renal cell carcinomaHISTOPATHOLOGY, Issue 6 2008B Ingold Aims:, The distinction between central nervous system (CNS) metastases of clear cell renal cell carcinoma (RCC) and CNS haemangioblastoma still poses a challenge to the pathologist. Since both entities occur in von Hippel,Lindau disease, this aggravates the issue. The antibody renal cell carcinoma marker (RCC-ma) has been suggested to identify primary RCCs specifically, but its value for diagnosing metastases of RCC is controversial. The aim was to assess two distinct clones of the RCC-ma for their potential to: (i) identify primary RCCs and (ii) differentiate between CNS metastases of clear cell RCC and CNS haemangioblastomas. Methods and results:, Using tissue microarrays, 77% (n = 363; PN-15) and 66% (n = 355; 66.4C2) of clear cell RCCs, and 93% (PN-15) and 74% (66.4C2) of papillary RCCs (n = 46) were immunopositive for RCC-ma, whereas none of the investigated chromophobe RCCs (n = 22) or any of the oncocytomas (n = 15) showed immunoreactivity. Importantly, 50.9% of CNS metastases of clear cell RCCs (n = 55) exhibited RCC-ma expression, whereas all CNS haemangioblastomas (71) were negative. Conclusions:, Both RCC-ma clones, despite some variation in their sensitivity to detect clear cell and papillary RCCs, are of value in differentiating subtypes of primary RCC and are excellent markers for discriminating clear cell lesions in the brain. [source] Mutations in the von Hippel-Lindau (VHL) gene refine differential diagnostic criteria in renal cell carcinomaJOURNAL OF SURGICAL ONCOLOGY, Issue 1 2002Nandita Barnabas PhD Abstract Background and Objectives Renal cell carcinomas (RCC) with abundant granular cytoplasm include oncocytomas, eosinophillic variants of chromophobe RCC, papillary RCC, collecting duct carcinoma, and some conventional (clear cell) RCC. Tumors with predominantly clear cell cytoplasm include typical chromophobe RCC and conventional (clear cell) RCC. The objective of this study was to determine if mutations in the VHL gene can serve as auxiliary diagnostic criteria in refining histology based subtyping of renal epithelial neoplasia. Methods The study cohort of 67 cases included 24 conventional RCC, 14 chromophobe RCC, 14 papillary RCC, and 15 oncocytomas. Single strand conformational polymorphism (SSCP) was used as a screening procedure for mutations followed by automated sequencing to identify mutations. Results Thirteen of the 14 mutations identified were novel, seven of which were in the coding region. In chromophobe RCC, mutations clustered in the 5,UTR/promoter region and have not been previously reported. Exon 3 appeared to favor conventional (clear cell) RCC and correlated with a more aggressive phenotype. Mutations were absent in the papillary and oncocytoma RCC subtypes. Conclusions Exon 3 mutations permitted a morphological distinction between conventional (clear cell) RCC and chromophobe RCC with clear cells. Mutations in the VHL gene refine histologic diagnostic criteria in RCC serving as adjuncts to the present morphology based diagnosis of RCC. J. Surg. Oncol. 2002;80:52,60. © 2002 Wiley-Liss, Inc. [source] Loss of heterozygosity of DNA repair gene, hOGG1, in renal cell carcinoma but not in renal papillary adenomaPATHOLOGY INTERNATIONAL, Issue 6 2008Neriman Gokden The kidney is constantly exposed to free radicals due to its active metabolism and processing of toxic metabolites. Among 20 or so free radical-induced DNA lesions, 8-oxoquanine is the most abundant and is potentially mutagenic if not sufficiently removed. The human 8-oxoquanine DNA glycosylase 1 (hOGG1) gene repairs 8-oxoguanine and resides at 3p25,26, which has frequent loss of heterozygosity (LOH) in clear cell,renal cell carcinoma (CC-RCC). Even though some studies found similar genetic alterations between renal papillary adenomas (PA) and papillary RCC (PRCC), no studies have been conducted to compare the alterations of hOGG1 gene in PA, PRCC and CC-RCC. To further explore the relationship between CC-RCC, PRCC and PA at the genetic level LOH of hOGG1 gene was investigated in these three groups. It was found that 8/8 PRCC (100%) and 8/9 CC-RCC (88%) had evidence of hOGG1 LOH, whereas all four PA (0%) were devoid of hOGG1 LOH. It is concluded that deletion of hOGG1 gene occurs commonly in PRCC and CC-RCC but not in renal cortical PA. Further studies are warranted to further explore the exact roles of hOGG1 gene in the development and progression of RCC. [source] Different vascular endothelial growth factor (VEGF), VEGF-receptor 1 and -2 mRNA expression profiles between clear cell and papillary renal cell carcinomaBJU INTERNATIONAL, Issue 3 2006BÖRJE J. LJUNGBERG OBJECTIVES To examine vascular endothelial growth factor (VEGF), VEGF-receptor-(R)1, and R2 mRNA levels in renal cell carcinoma (RCC), a tumour generally refractory to most medical therapy, but for which a potentially useful therapeutic alternative is inhibition of angiogenesis. PATIENTS AND METHODS VEGF, VEGF-R1 and -R2 mRNA levels were analysed using the quantitative reverse transcription-polymerase chain reaction. RNA was extracted from 84 conventional (clear cell) RCCs (cRCC), 20 papillary (pRCC), six chromophobe (chRCC), and 27 corresponding kidney cortex tissues, obtained from 110 patients in whom high-quality RNA was available from the tumours (53 women and 57 men, mean age 64.7 years, range 25,85). RESULTS The VEGF, VEGF-R1, and -R2 mRNA levels were higher in tumour than in kidney cortex tissues. Among the RCC types, cRCC had higher VEGF levels than pRCC. In cRCC, VEGF-R2 levels were higher in stage I,II than in more advanced stages. In pRCC, VEGF and VEGF-R2 levels were higher in stage III than in stage I,II tumours. In cRCC, patients with VEGF levels below the median had a significantly shorter survival time than those with higher levels. By contrast, in pRCC, VEGF, VEGF-R1 and -R2 RNA levels above the median were related to adverse survival. Using multivariate analysis in cRCCs, VEGF-R1 mRNA level was the last factor to be omitted after stepwise elimination analysis. CONCLUSION VEGF and its receptors were associated with tumour stage and survival, but were not independent prognostic factors. Different RCC types had different expression patterns of VEGF and receptor mRNA levels. We conclude that different pathways might be involved in regulating angiogenesis in the specific RCC types. Detailed knowledge of angiogenesis in RCC is essential when designing new treatment trials where angiogenesis inhibition is used. [source] Mucinous but not clear cell histology is associated with inferior survival in patients with advanced stage ovarian carcinoma treated with platinum-paclitaxel chemotherapy,CANCER, Issue 6 2010Aristotle Bamias MD Abstract BACKGROUND: Mucinous and clear cell histology have been associated with adverse prognosis in ovarian carcinomas. The authors compared the outcome of these subtypes with that of serous tumors in patients who were treated with combination paclitaxel/platinum at their center. METHODS: Four hundred twenty patients with histologically confirmed, serous (n = 367), mucinous (n = 24), or clear cell (n = 29) ovarian carcinomas, International Federation of Gynecology and Obstetrics stage III or IV disease, and who were treated with paclitaxel/platinum after cytoreductive surgery were included in this analysis. RESULTS: The median overall survival for each histological subtype was 47.7 months (95% confidence interval [CI], 37.7-57.7 months) for serous, 15.4 months (95% CI, 4.2-26.6 months) for mucinous, and 36.6 months (95% CI, 22.7-50.5 months) for clear cell carcinomas. Cox regression analysis showed that mucinous histology was an independent predictor of poor prognosis compared with serous tumors (hazard ratio, 0.360; 95% CI, 0.215-0.603; P = .001). In contrast, such a difference between clear cell and serous carcinomas was not found (P = .337). Median survival of patients with mucinous tumors and residual disease >2 cm was poor, averaging 7.1 months (95% CI, 4.6-9.6 months). CONCLUSIONS: Mucinous but not clear cell histology is associated with significantly worse prognosis in advanced ovarian cancer treated with combination platinum/paclitaxel. Different therapeutic strategies should be studied in this entity. Cancer 2010. © 2010 American Cancer Society. [source] CA-125 change after chemotherapy in prediction of treatment outcome among advanced mucinous and clear cell epithelial ovarian cancers,CANCER, Issue 7 2009A Gynecologic Oncology Group study Abstract BACKGROUND: There are limited data regarding unique clinical or laboratory features associated with advanced clear cell (CC) and mucinous (MU) epithelial ovarian cancers (EOC), particularly the relationship between CA-125 antigen levels and prognosis. METHODS: A retrospective review of 7 previously reported Gynecologic Oncology Group phase 3 trials in patients with stage III/IV EOC was conducted. A variety of clinical parameters were examined, including the impact of baseline and changes in the CA-125 level after treatment of CC and MU EOC on progression-free (PFS) and overall survival (OS). RESULTS: Clinical outcomes among patients with advanced CC and MU EOC were significantly worse when compared with other cell types (median PFS, 9.7 vs 7.0 vs 16.7 months, respectively, P < .001; median OS, 19.4 vs 11.3 vs 40.5 months, respectively, P < .001). Suboptimal debulking was associated with significantly decreased PFS and OS among both. Although baseline CA-125 values were lower in CC (median, 154 ,/mL) and MU (100 ,/mL), compared with other cell types (275 ,/mL), this level did not appear to influence outcome among these 2 specific subtypes of EOC. However, an elevated level of CA-125 at the end of chemotherapy was significantly associated with decreased PFS and OS (P < .01 for all). CONCLUSIONS: Surgical debulking status is the most important variable at prechemotherapy predictive of prognosis among advanced CC and MU EOC patients. Changes in the CA-125 levels at the end treatment as compared with baseline can serve as valid indicators of PFS and OS, and likely the degree of inherent chemosensitivity. Cancer 2009. © 2009 American Cancer Society. [source] Expression of epithelial membrane protein-2 is associated with endometrial adenocarcinoma of unfavorable outcome,CANCER, Issue 1 2006Madhuri Wadehra PhD Abstract BACKGROUND Epithelial membrane protein 2 (EMP2) is an estrus-regulated tetraspan protein that is required for endometrial competence in blastocyst implantation. EMP2 controls surface levels of several classes of integrin and other cell-interaction molecules, and their trafficking to glycolipid-enriched lipid raft domains is important in receptor signaling. These features suggest that EMP2 may contribute to neoplastic traits of endometrial cancer. The objective of this study was to determine the prevalence of EMP2 expression in endometrial neoplasms and its clinical significance. METHODS EMP2 immunophenotype, histologic diagnosis, grade, the presence of lymphovascular invasion, disease stage, and clinical follow-up were determined for 99 endometrial cancers. RESULTS Significant EMP2 expression (EMP2 positive) was observed in 12 of 99 cancers (9 endometrioid [6 International Federation of Gynecology and Obstetrics Grade 3], 1 serous, 1 mixed endometrioid and serous, and 1 mixed endometrioid and clear cell), and weak EMP2 expression was observed in 11 cancers. EMP2-positive tumors were more likely than others to be myometrium invasive, high stage, and recurrent, persistent, or fatal. The overall median survival for patients with EMP2-positive tumor was only 23 months, whereas the medial survival was not reached for patients with EMP2-weak and EMP2-negative tumors. The median disease-free interval was only 11 months for patients with EMP2-positive tumors and was not reached for patients with EMP2-weak and EMP2-negative tumors. A multivariate analysis of disease-free survival demonstrated independent, negative prognostic significance for EMP2 expression, high stage, and high-risk histologic subtypes. CONCLUSIONS EMP2 expression is a feature of some prognostically unfavorable endometrial cancers. Its utility for clinical decision making and its biologic role in endometrial cancer deserves further study in a larger series of patients. Cancer 2006. © 2006 American Cancer Society. [source] Rhabdomyoma of the head and neck: Clinicopathologic features of two casesHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 8 2003Gianfranco Favia MD Abstract Background. Extracardiac rhabdomyomas are rare benign tumors of the head and neck. They are frequently misdiagnosed and possibly overtreated when confused with other aggressive tumors. Methods. This article reports on the clinicopathologic features of two such tumors affecting adult patients and initially seen as slowly-growing, indolent neoplasms. Results. The tumors were of fibrous consistency, mobile, with well-demarcated borders and evident lines of cleavage. Both patients were treated by conservative surgery and remained disease-free after prolonged clinical observation. Histologically, both tumors were composed of large eosinophilic cells intermingled with polyhedral clear cells. Both cell types contained abundant glycogen accumulations. Conclusions. The differential diagnosis is with granular cell tumor and with sarcomas, the former being easily distinguishable morphologically, and the latter be seen with more rapid growth and adherence to the adjacent tissues. On the basis of the preceding features, rhabdomyomas can be suspected at a preoperative stage and adequately managed with enucleation or simple excision. © 2003 Wiley Periodicals, Inc. Head Neck 25: 700,704, 2003 [source] Apocrine carcinoma of the vulva in a band-like arrangement with inflammatory and telangiectatic metastasis via local lymphatic channelsINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2003Takahiro Kiyohara MD Background Primary adenocarcinomas of the vulva have been classified as sweat gland carcinomas, extramammary Paget's disease, and primary breast carcinomas of the vulva. They share some common histopathologic features. Methods We describe a 72-year-old Japanese woman with apocrine carcinoma of the vulva and local lymphatic metastasis. Results The patient presented with a bruise on her inguinal area. Physical examination revealed a 4 cm × 7 cm, dark-red, irregularly elevated tumor on the left labium majora. Dome-shaped, flesh-colored, small papulovesicles were scattered on the abdomen, accompanied by erythema and induration. The lesion showed a band-like arrangement. General examination revealed multiple bone metastases, particularly in the spine. Microscopic examination revealed a moderately differentiated adenocarcinoma with signet ring cells. A few pagetoid clear cells were present in the hypertrophic epidermis. The peripheral papulovesicles demonstrated the same histopathologic view as in inflammatory and telangiectatic, metastatic breast carcinoma. Tumor cells were positive for various ductal and glandular markers. Estrogen and progesterone receptors were not expressed. Ultrastructural findings suggested differentiation towards apocrine or mammary glands because of the presence of an apocrine process and electron-dense mucous granules. The patient died in spite of combination chemotherapy and irradiation therapy. Conclusions We report a rare case of apocrine carcinoma of the vulva in a band-like arrangement with local lymphatic metastasis which showed the clinical and histopathologic characteristics of inflammatory and telangiectatic carcinoma. [source] Electron microscopic study to compare preclinical Cushing's syndrome with overt Cushing's syndromeINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2002Daisaku Hirano Abstract Background: No significant differences in gross and light- microscopic features have been reported between preclinical and overt Cushing's adenomas. In this study, the ultrastructural differences between the two syndromes was attempted to be clarified. Methods: Two preclinical Cushing's syndrome adenomas and two overt Cushing's syndrome adenomas obtained from surgical extirpation were examined in an electron microscopic study. Results: Light microscopically, the adenomas of both syndromes were composed predominantly of clear cells, with few compact cells. Ultrastructurally, the prominent differences were of development in each organelle: the preclinical Cushing's adenomas had undeveloped mitochondria, which were smaller in size and had sparse cristae, lysosomes and polysomes, whereas the overt Cushing's adenomas contained well-developed mitochondria which were larger in size and were filled with abundant cristae, smooth endoplasmic reticulum (SER), lysosomes and polysomes. Conclusions: Preclinical Cushing's syndrome adenomas were ultrastructurally characterized by a reduced number of cellular organelles such as mitochondria and SER, which are necessary to synthesize glucocorticoid hormones. However, examination of a greater number of adenomas will be required to be able to draw conclusions on the ultrastructural differences between the two syndromes. [source] Clear cell myoepithelial carcinoma of the skin.JOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2009A case report Myoepitheliomas are tumors of myoepithelial cells, most frequently diagnosed in the salivary glands. Cutaneous location is very rare, especially for malignant variant. We report a case of recurrent cutaneous myoepithelial carcinoma of the femoral region in a 51-year-old woman. Histologically, the tumor was confined to the dermis and superficial subcutaneous fat tissue, exhibiting typical multinodular pattern. The majority of tumor cells were of clear cell type, although rare epithelioid and spindle cells were also present. Nuclear atypia, mitotic activity of 12 mitoses per 10 microscopic high power fields and Ki-67 labeling index of 20%, as well as three recurrences, corroborated the malignant nature of the tumor. Immunohistochemistry showed positivity for cytokeratin, epithelial membrane antigen, vimentin, S-100 protein and myogenic markers (,-smooth muscle actin and muscle-specific actin HHF-35) in keeping with the myoepithelial cell immunophenotype. Staining for CD34, desmin and HMB-45 was negative. Myoepithelial carcinoma should be considered in the differential diagnosis of cutaneous neoplasms composed predominantly of clear cells. [source] Squamous cell apocrine hidradenomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 10 2007Jorge Angulo Apocrine hidradenoma is a benign adnexal neoplasm with apocrine differentiation. The neoplasm is composed of four different types of epithelial cells, including pale or clear cells, polygonal cells, mucinous cells and squamous cells, with variable proportions of them from case to case. In most examples of this neoplasm, clear or the polygonal cells are predominant, whereas the other types of neoplastic cells are less abundant. We report two cases of apocrine hidradenoma mostly composed of squamous cells. Histopathologic examination showed that the neoplasms were composed of both solid and cystic areas. The solid aggregations of neoplastic cells were composed of a peripheral layer of basaloid polygonal cells, whereas squamous cells forming the bulk of the aggregations. These squamous cells showed large eosinophilic cytoplasm and vesicular nuclei with prominent nucleoli. In one case, small foci of mucinous cells could also be seen in some aggregations of neoplastic cells, mostly around ductal structures. In both the cases, some of the tubular structures lined by epithelial cells showed evidence of decapitation secretion in their luminal border. The neoplastic stroma consisted of sclerotic collagen bundles when compared with adjacent normal dermis, and artefactual clefts separated the neoplasms from the surrounding tissue. The rare cases described in this report are exceptional because most of the neoplastic cells showed squamous appearance and for that reason we think that squamous cell apocrine hidradenoma is the most appropriate name for these neoplasms. [source] A case of cutaneous myoepithelial carcinomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2007Jin Tanahashi Background:, Cutaneous myoepithelioma, both benign and malignant, is a rare neoplasm composed of neoplastic myoepithelial cells showing diverse histopathological features, and criteria for discriminating benign or malignant have not been fully clarified. Patient:, We present a case of cutaneous myoepithelial carcinoma in a 62-year-old woman presenting a solid mass in the right back. Results:, Resected tumor was located in the whole dermis and subcutis. Histopathologically, two different growth patterns were noted: a small-nested or trabecular pattern in the superficial part and a large nodular pattern with extensive central necrosis in the deep part. Tumor cells were all epithelioid, although plasmacytoid and glycogen-rich clear cells were also observed within the large nodules of the deep part. Immunohistochemically, the cells were positive for both epithelial and myogenic markers, suggesting myoepithelial origin. Lymphatic invasion and lymph node metastasis were evident despite inconspicuous atypia and low mitotic rate. Conclusion:, The final diagnosis was cutaneous myoepithelial carcinoma. At present, it seems to be difficult to predict the behavior of myoepithelioma of the skin and soft tissue, although atypia and high mitotic rate are reported to be associated with local recurrence and metastasis. [source] Pagetoid dyskeratosis of the prepuce.JOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2000An incidental histologic finding resembling extramammary Paget's disease Background: Pale cells resembling those of paget's disease have been seen as an incidental finding within the epidermis in a variety of benign papules most commonly located in intertriginous areas. This lesion, called pagetoid dyskeratosis, is considered a reactive process in which a small part of the normal population of keratinocytes is induced to proliferate. Among the inductors friction is suspected. As far as we know, these cells have not been reported in the penis. Methods: Here we describe the location of the lesion in the foreskin and the incidence of this lesion in a group of 281 unselected patiets surgically treated for phimosis. In selected cases histochemical staining and immunohistochemical studies were performed. Results: Pagetoid dyskeratosis was found in 105 cases (37.4%) but only in 5 cases (1.8%) the lesion was conspicuous. The cells of pagetoid dyskeratosis show an immunohistochemical profile different from the surrounding keratinocytes characterized by premature keratinization. Pagetoid dyskeratosis cells must be distinguished from the artefactual clear cells of the epidermis, from reactive melanocytes, and from pale-cell acanthosis. In cases in which pagetoid dyskeratosis shows a florid expression there is a hazard of overdiagnosis to the patient. The main differential diagnosis includes extramammary Paget's disease, pagetoid squamous cell carcinoma in situ, epidermotropic metastasis, superficial spreading malignant melanoma, clear cell papulosis, and penile koilocytoses. Conclusions: The pathologist should be familiar with the histologic features of pagetoid dyskeratosis in the foreskin in order to avoid misdiagnosis and unnecessary treatment. Routine histologic study is usually sufficient to identify the lesion. [source] Odontogenic ghost cell tumour with clear cell components: clear cell odontogenic ghost cell tumour?JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 6 2004Jung Hoon Yoon A case of odontogenic ghost cell tumour (OGCT) with clear cell components was encountered in the mandible of a 63-year-old man. The tumour revealed ameloblastomatous-type epithelial components accompanied by clusters of ghost cells and dentinoid juxtaposed to the odontogenic epithelium. In addition, some areas of the tumour tissue showed sheets and islands of clear, glycogen containing epithelial cells, which were separated by a thin fibrous connective tissue stroma. Both ameloblastic and clear cells exhibited positive immunoreactivities for cytokeratin 19 and AE1/3. It is not known whether this tumour represents a clear cell change of a pre-existing OGCT or a separate and distinct neoplasm derived de novo from the odontogenic epithelium. This tumour was given the term ,clear cell OGCT' because it captures the clear cell components, which is one of the most prominent distinguishing features of the tumour. [source] Mutations in the von Hippel-Lindau (VHL) gene refine differential diagnostic criteria in renal cell carcinomaJOURNAL OF SURGICAL ONCOLOGY, Issue 1 2002Nandita Barnabas PhD Abstract Background and Objectives Renal cell carcinomas (RCC) with abundant granular cytoplasm include oncocytomas, eosinophillic variants of chromophobe RCC, papillary RCC, collecting duct carcinoma, and some conventional (clear cell) RCC. Tumors with predominantly clear cell cytoplasm include typical chromophobe RCC and conventional (clear cell) RCC. The objective of this study was to determine if mutations in the VHL gene can serve as auxiliary diagnostic criteria in refining histology based subtyping of renal epithelial neoplasia. Methods The study cohort of 67 cases included 24 conventional RCC, 14 chromophobe RCC, 14 papillary RCC, and 15 oncocytomas. Single strand conformational polymorphism (SSCP) was used as a screening procedure for mutations followed by automated sequencing to identify mutations. Results Thirteen of the 14 mutations identified were novel, seven of which were in the coding region. In chromophobe RCC, mutations clustered in the 5,UTR/promoter region and have not been previously reported. Exon 3 appeared to favor conventional (clear cell) RCC and correlated with a more aggressive phenotype. Mutations were absent in the papillary and oncocytoma RCC subtypes. Conclusions Exon 3 mutations permitted a morphological distinction between conventional (clear cell) RCC and chromophobe RCC with clear cells. Mutations in the VHL gene refine histologic diagnostic criteria in RCC serving as adjuncts to the present morphology based diagnosis of RCC. J. Surg. Oncol. 2002;80:52,60. © 2002 Wiley-Liss, Inc. [source] Pigmented ependymoma with signet-ring cells and Rosenthal fibers: A rare variant of ependymomaNEUROPATHOLOGY, Issue 1 2010Yesim Ertan We report a rare case of ependymoma with vacuolar features, signet cells, pigmentation and numerous Rosenthal fibers arising in the fourth ventricle of a 35-year-old woman. The tumor was composed of cells with cytoplasmic vacuoles, signet cells and clear cells. The clear cells were compactly arranged resembling oligodendroglioma. Pseudovascular and ependymal rosettes were observed only in focal areas. Additionally, some tumor cells contained brown cytoplasmic pigment, which was histochemically compatible with lipofuscin and neuromelanin. On immunohistochemical examination, the tumor cells were positive for S100, glial fibrillary acidic protein and vimentin, and negative for synaptophysin, cytokeratin, neurofilament and HMB45. Epithelial membrane antigen staining showed dot-like and small vesicular reactivity. The case is presented to increase familiarity with these extraordinary variants of ependymoma. [source] Clear cell ependymoma: a mimicker of oligodendroglioma , report of three casesNEUROPATHOLOGY, Issue 4 2008Deepali Jain Clear cell variant of ependymoma is a rare entity which morphologically mimics oligodendroglioma and poses a diagnostic dilemma. We describe three cases of clear cell ependymoma in male children which were supratentorial in location. On microscopic examination, these tumors were composed of sheets of clear cells and resembled oligodendroglioma. Electron microscopy confirmed the ependymal nature of these tumors. Clear cell ependymomas are rare and aggressive tumors. More cases need to be reported to determine their therapeutic responsiveness and prognosis. [source] Cystadenoma of the palate: Immunohistochemistry of mucinsPATHOLOGY INTERNATIONAL, Issue 8 2008Kimihide Kusafuka Cystadenoma is a relatively rare benign epithelial tumor of the salivary glands, and described herein is an additional case. A 51-year-old Japanese man had noticed a mass of the left hard palate 25 years previously. Macroscopically, the resected specimen was a multicystic lesion. Histologically, the tumor was composed of bilayered columnar epithelium with cystic change and partial solid growth of glandular structures with clear cells. The tumor cells had mild cellular atypia, but the tumor lacked papillary growth and a fibrous capsule. Immunohistochemistry was positive for cytokeratins, epithelial membrane antigen, MUC1, MUC4 and MUC6, but negative for myoepithelial markers, MUC2, MUC5AC and MUC5B. Such MUC expression patterns suggested that cystadenoma occurs from excretory ducts. [source] Case of combined adrenal cortical adenoma and myelolipomaPATHOLOGY INTERNATIONAL, Issue 9 2004Takaharu Matsuda We report a case of myelolipoma 10 mm in size within a functional cortical adenoma that was 33 × 22 × 17 mm in size. A 29-year-old woman was referred to hospital for transient hypertension. A right adrenal tumor was detected by computed tomography (CT) scan and magnetic resonance imaging (MRI). Her cortisol levels indicated a loss of the normal diurnal pattern, and urinary 17-hydroxycorticosteroids was elevated. She underwent a right adrenalectomy under the diagnosis of adrenal adenoma with Cushing's syndrome. The tumor was fairly well encapsulated by a thin layer of connective tissue. The major tumor portion was composed of two distinct cell types, clear cells and eosinophilic cells, arranged in an alveolar structure. These findings were representative of cortical adenoma. The adrenal cortical adenoma centrally included well-demarcated adipose tissue admixed with scattered islands of myelopoietic elements: erythroblasts, myeloid cell series and lymphocytic cells, which was eventually recognized as myelolipoma. Recently, adrenal myelolipoma has commonly been found because of the ease of detecting it as an incidentaloma by CT scan or MRI. However, the present adrenal myelolipoma case is uncommon because it is combined with a functioning cortical adenoma. Only six similar cases have previously been reported in English and Japanese publications. Furthermore, in the present case, the myelolipoma formed a tumor nodule, and to our knowledge, this is the first reported case of a radiographically recognizable tumor nodule. We discuss the etiology of myelolipoma and suggest that myelolipoma can develop in the course of endocrine hyperfunction. [source] Metastasis of renal cell carcinoma to central nervous system hemangioblastoma in two patients with von Hippel,Lindau diseasePATHOLOGY INTERNATIONAL, Issue 12 2001Shuji Hamazaki Here we report tumor-to-tumor metastases identified in two patients with von Hippel,Lindau (VHL) disease. The first patient had bilateral renal carcinomas and multiple cerebellar hemangioblastomas, and the second patient had a renal carcinoma and multiple hemangioblastomas in the retina, cerebellum and spinal cord. A cerebellar lesion from the first patient and a spinal lesion from the second patient contained two distinct components. The inner part of these tumors consisted of a nested mass of polygonal clear cells that expressed cytokeratin and epithelial membrane antigen, while the outer part of the tumors showed proliferation of capillaries and intervening foamy stromal cells that were negative for cytokeratin and epithelial membrane antigen. The tumors were thus considered to be hemangioblastomas complicated by metastatic lesions of renal cell carcinoma of clear cell type. These cases indicate that tumor-to-tumor metastasis should be considered when hemangioblastoma contains a clear cell carcinoma component in the setting of VHL disease, and that immunohistochemical staining for cytokeratin and epithelial membrane antigen is useful for the diagnosis. [source] Low-grade renal cell carcinoma arising from the lower nephron: A case report with immunohistochemical, histochemical and ultrastructural studiesPATHOLOGY INTERNATIONAL, Issue 12 2001Masako Otani Most renal cell carcinomas (RCC) are composed of clear cells with sinusoid-like vasculatures and originate from the proximal tubule. On the other hand, collecting duct carcinoma (CDC) and chromophobe RCC are thought to originate from the lower nephron. In the present study, we present a case of unusual RCC. The patient was a 68-year-old Japanese woman who had developed general fatigue with hematuria. Computed tomography revealed a left renal tumor suggesting sarcoma. The resected tumor was located in the renal parenchyma, measuring 12 × 10 × 8 cm in size. Histologically, the tumor consisted principally of cuboidal cells forming parallel or radiating arrays, continuous with the spindle-shaped cells. Most parts of the tumor showed hemorrhagic necrosis. Immunohistochemically, tumor cells were positive for high molecular weight cytokeratins, vinculin, vimentin, CD15 and epithelial membrane antigen, and showed affinities with some kinds of lectins. N- and E-cadherins and , -catenin were diffusely positive in tumor cells. Nuclear positivity for Ki-67 and p53 protein were approximately 2.0 and 1.7%, respectively. Considering its morphological and histochemical natures, this tumor is considered to have originated from the lower nephron, which is unique for a tumor of low-grade malignancy. [source] Structure of the Lining Epithelium of the Cauda Epididymis of the Golden HamsterANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009C. C. L. Beu Summary The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes (¾ of basal cytoplasm), and vacuoles and vesicles (¼ of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster. [source] Ultrastructural Features in the Epididymis of the Dog (Canis familiaris, L.)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2001Bruno Cesar Chimming The ultrastructure of the epididymal duct of the dog is described in this paper. The epididymis was divided into three morphofunctional segments: initial, middle and terminal. The cellular population of the lining epithelium is formed from principal, apical, basal and clear cells. The peritubular stroma and the tubular interstitium surrounding the epithelium are also described. The outcome is compared to the description made in other species of mammals. [source] Establishment and characterization of seven human renal cell carcinoma cell linesBJU INTERNATIONAL, Issue 1 2000K.-H. Shin Objective,To establish human renal cell carcinoma (RCC) cell lines, and to investigate the cell phenotypes and molecular characteristics of human RCC cell lines and their corresponding tumour tissues. Materials and methods,Seven human RCC cell lines from pathologically proven RCCs were established. The histopathology of the primary tumours, in vitro growth characteristics and status of tumour suppressor genes, mismatch repair genes and microsatellite instability (MSI) were examined in cell lines and their corresponding tumour tissues. Five of the cell lines were derived from clear cells (SNU-228, -267, -328, -349, and -1272), one from granular cells (SNU-482), and one from mixed clear and granular cell types (SNU-333). The mutational status was compared for von Hippel-Lindau (VHL), p53, TGF-, type II receptor (TGF-,RII), hMSH2, and hMLH1 genes in the cell lines and their corresponding tumour tissues. The MSI status of the cell lines was determined by screening for adenine repeat sequences, e.g. BAT-25, BAT-26, and BAT-40. Results,All lines showed different doubling times and were confirmed by DNA fingerprinting analysis to be unique. Contamination by mycoplasma or bacteria was excluded. In two cell lines (SNU-349 and -1272) and their tumour tissues, mutations in the VHL gene were found. The SNU-267 line had a frameshift mutation in the p53 gene. A missense mutation of the TGF-,RII gene was detected in the SNU-1272 line and the corresponding tissue. Analysis of the repeat sequences showed one cell line (SNU-349) to have MSI and the other six to have microsatellite stability. As MSI is a hallmark of the inactivation of mismatch repair genes, the presence of hMSH2 and hMLH1 mutations was investigated in all seven cell lines. An inactivating homozygous single base-pair deletion of the hMLH1 gene was found only in the SNU-349 cell line and corresponding tissue. Moreover, a frameshift mutation within an 8-bp polyadenine repeat present in the hMSH3 coding region was found only in the MSI cell line and tumour tissue. Conclusion,These newly established RCC cell lines should provide a useful in vitro model for studies related to human RCC. The SNU-349 cell line should be especially useful for studies of MSI and mismatch repair-defective RCCs. [source] | ||||||||||||||||||||||||||||