1/19. A peculiar factor viii-related antigen staining of an oxyphilic cell nodule within an intrathyroidal parathyroid adenoma.A case of intrathyroidal parathyroid adenoma, which was found in the lower portion of the right thyroid lobe, is presented. The nodule in this lesion was composed of oxyphilic cells. In order to verify a possible vascular invasion, immunohistochemical study with factor viii-related antigen/von willebrand factor, which is known to be synthesized by the endothelial cells and stored in weibel-palade bodies, and ulex europaeus lectin 1 were applied. It was interesting to find positivity for factor viii-related antigen and ulex europaeus lectin I strictly confined in the nodule of oxyphil cells, which are known to have large numbers of mitochondria. This led to investigating similar immunoreactions in different lesions of oxyphilic cells with several other markers. The possible cross-reaction between weibel-palade bodies and mitochondria deserves further detailed research.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/19. Multicentric oncocytoma of the lung diagnosed by fine-needle aspiration.A 50-yr-old man presented with dyspnea. On chest X-ray, multiple pulmonary nodules were observed. Fine-needle aspiration biopsy (FNAB) showed tridimensional aggregates of atypical round epithelial cells, containing numerous cytoplasmic granules. The tissue fragment confirmed the presence of an epithelial tumor composed of trabecular sheets of clear cells, with numerous cytoplasmic granules which stained with phosphotungstic acid hematoxylin (PTAH). Immunohistochemically, the tumor cells were positive for cytokeratins and antimitochondrial antigen, whereas chromogranin, synaptophysin, S-100 protein, and HMB-45 were negative. Clinical and tomographic studies ruled out any tumor mass elsewhere. The rarity of this lesion in the lung and the potential difficulties for its diagnosis prompted us to report the clinical, cytological, and immunohistochemical findings in this case.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
3/19. Renal oncocytoma with intracytoplasmic lumina: a case report with ultrastructural findings of "oncoblasts".The authors present a case of renal oncocytoma with numerous intracytoplasmic lumina in a 45-year-old woman, with an emphasis on the ultrastructural findings of so-called oncoblasts. The tumor was located in the upper pole of the left kidney, measuring about 3.3 cm in diameter. Histologically, it was composed of solid nests or acinar growths of so-called oncocytic tumor cells with numerous intracytoplasmic lumina and scattered foci of so-called oncoblasts. The luminal surface was positive for Hale's colloidal iron stain. A very small number of glycogen-containing cells were found scattered in a few nests. Immunohistochemically, tumor cells were positive for cytokeratin and epithelial membrane antigen, but negative for vimentin and carcinoembryonic antigen. The Ki-67 labeling index was 1.2%. All of the Ki-67-positive cells were oncocytes. So-called oncoblasts were negative for Ki-67. Ultrastructural examination revealed that the predominant tumor cells had cytoplasm packed with round mitochondria and the mitochodria had lamellar long cristae. So-called oncoblasts showed scant cytoplasm with a moderate number of small mitochondria. Some of them showed pyknosis which can be regarded as mitochondrial involution. The authors believe that so-called oncoblasts are damaged or involuted oncocytes rather than precursors of oncocytes.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
4/19. Mixed tumors, myoepitheliomas, and oncocytomas of the soft tissues are likely members of the same family: a clinicopathologic and ultrastructural study.Four diagnostically unusual soft tissue tumors are presented. All lesions were of consistent size and long duration. Histologically, one lesion was analogous to mixed tumors of the usual sites (i.e., salivary glands), one lesion was totally spindled, and the two other lesions both had oncocytic appearances (epithelioid and spindle biphasic pattern in a case, purely epithelioid in the other). Immunohistochemically, the mixed tumor was positive for vimentin, cytokeratins, S-100 protein, and focally for EMA. The purely spindled tumor exhibited immunoreactivity for vimentin, actins, S-100 protein, EMA (focally), and GFAP. The oncocytic biphasic tumor was positive for mitochondrial antigen, vimentin, and actins. The purely epithelioid oncocytic neoplasm was immunoreactive only for mitochondrial antigen and vimentin. Ultrastructurally, in the epithelial-like portion of the first (mixed) tumor, peripheral arrays of contractile filaments were detected along with well-developed desmosomes. In the second (spindled) case, peripheral contractile filaments and attenuated desmosomes were also seen. In the third case, a huge number of mitochondria, some desmosomes, and actin-type microfilaments were found. In the fourth case, desmosomes and punctate subplasmalemmal densities, in addition to numerous mitochondria, were documented. In all cases an external basal lamina were present, which was discontinuous in the first three cases and almost continuous in the fourth. These tumors were respectively designated as mixed tumor, myoepithelioma of the classic type, myoepithelioma of oncocytic type with biphasic cell architecture, and true oncocytoma. So far, all tumors have followed benign clinical courses (median follow up: 12 months). Comparisons with similar tumors of other sites are drawn, and suggestions for considering all of them as members of the same myoepithelial-derived tumor family are given.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
5/19. Angiotropic lymphoma occurring in a lacrimal sac oncocytoma.This report describes a case of angiotropic variant of diffuse large B cell lymphoma within a benign oncocytoma of the lacrimal sac. The occurrence of this rare lymphoma within a benign neoplasm has not been documented previously. An 87 year old woman presented with a swelling over the area of the left lacrimal sac, which histological examination revealed to be an oncocytoma. Many small blood vessels within the tumour were filled with large cytologically atypical cells, which stained positively for leucocyte common antigen and a B cell antigen, CD20, confirming the presence of a large B cell non-Hodgkin's lymphoma of angiotropic type. Angiotropic lymphoma is a very rare and usually highly aggressive variant of non-Hodgkin's lymphoma, which classically involves the central nervous system and skin, but has been described within most organs. Its occurrence within a benign neoplasm is probably coincidental, although a close association between oncocytic epithelium and normal lymphoid cells is recognised in Warthin's tumour of salivary and lacrimal glands.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
6/19. Cribriform-morular variant of papillary carcinoma: the sporadic counterpart of familial adenomatous polyposis-associated thyroid carcinoma. A case report with clinical and molecular genetic correlation.The increased incidence of thyroid carcinomas in familial adenomatous polyposis (FAP) patients is well recognised. These thyroid neoplasms display distinctive clinicopathological features and generally show good prognostic outcome. Recently, unusual sporadic tumours that share the morphological features of FAP-associated thyroid carcinomas have also been described. In this report, we document a case of a thyroid tumour in a previously well, 46-year-old female. histology revealed a circumscribed neoplasm composed of tubular, papillary, cribriform and solid areas. The pseudostratified columnar tumour cells showed occasional nuclear grooves and rare nuclear inclusions. immunohistochemistry showed positive staining with antibodies to cytokeratin AE1/AE3, oestrogen and progesterone receptor proteins. Focal immunoreactivity was also noted with antibodies to thyroglobulin, epithelial membrane antigen, 34betaE12 and cytokeratin CK7. The absence of polyps on colonoscopy and germline mutation in the adenomatous polyposis coli (APC) gene provides evidence that this tumour represents the sporadic counterpart of FAP-associated thyroid carcinoma. The patient is well with no evidence of disease 7 months following resection of the tumour. The differential diagnoses and molecular genetics of this unusual tumour are discussed.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
7/19. Adrenocortical oncocytic tumors: report of 10 cases and review of the literature.Ten additional adrenocortical oncocytic tumors are presented: 2 benign oncocytomas, 4 borderline oncocytomas of uncertain malignant potential, and 4 oncocytic carcinomas. Histologically all tumors were entirely or predominantly composed of oncocytes. Immunohistochemically all tumors were immunoreactive for mitochondrial antigen mES-13. Electron microscopy was performed in 8 cases and was confirmatory of the oncocytic cell change. The morphologic parameters of the Weiss system, considered to be predictive of the biologic behavior of conventional (nononcocytic) adrenocortical tumors, are reviewed in the context of their possible application to the oncocytic tumor variant. Proposed major criteria (high mitotic rate, atypical mitoses, venous invasion) and minor criteria (large size and huge weight, necrosis, capsular invasion, sinusoidal invasion) in distinguishing malignant tumors are discussed, and definitional criteria (predominantly cells with eosinophilic and granular cytoplasm, high nuclear grade, diffuse architectural pattern) in common with all types of oncocytic tumors are outlined. The authors' proposed working rules for diagnostic categorization of oncocytic adrenocortical tumors are defined, with the presence of 1 major criterion indicating malignancy, 1 to 4 minor criteria indicating uncertain malignant potential (borderline), and the absence of all major and minor criteria indicative of benignancy. Using these criteria, the diagnosis of malignancy was straightforward in 3 of the 4 cases designated as oncocytic carcinoma (presence of at least 2 major criteria and all the minor criteria), while in 1 case the original diagnosis of benign oncocytoma was reversed to malignant following critical review of the original pathologic material after local tumor recurrence. Tumor recurrence occurred in 2 carcinomas at 8 and 20 months, respectively, and was followed in 1 case by the patient's death. The third patient expired at 6 months from unrelated causes, and the fourth patient is free of disease at the relatively short follow-up interval of 6 months. Regarding the 4 patients with borderline tumors, all are alive with no evidence of disease, with follow-up ranging from 10 to 61 months (mean 38.7 months). The 2 benign tumors have a follow-up of 25 and 30 months, respectively. Diagnostic difficulties are delineated and a complete review of the literature on this topic has also been performed.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
8/19. Spindle cell oncocytoma of the adenohypophysis: report of two recurrent cases.The recently described "spindle cell oncocytoma of the adenohypophysis" is a very rare and often misdiagnosed entity. A benign biologic behavior has been suggested based on the absence of recurrences with a median follow-up of 3 years. Herein, we present 2 cases of recurrent spindle cell oncocytomas. One patient is a 71-year-old woman (case no. 1) and the other a 76-year-old man (case no. 2). Recently, both underwent transsphenoidal reexploration for recurrent "pituitary adenoma." Patient no. 1 had initial surgery 11 years ago with a recurrence after 3 years that was initially stable. Ultimately, a partial resection was performed after compression of optic pathways by the tumor, and approximately 1 year later, re-resection was carried out. Patient no. 2 had initial surgery 10 years ago with recurrence and resection after 3 years. He recently presented with a large mass that involved the pituitary fossa and base of the skull, with extension into the nasopharynx and nasal cavity. The primary and recurrent lesions of both cases showed similar architecture with interlacing fascicles of spindle cells that alternated with areas of epithelioid-like cells that exhibited eosinophilic, granular cytoplasm. Neoplastic cells were positive for vimentin, S-100 protein, and epithelial membrane antigen, and negative for glial fibrillary acidic protein, chromogranin, and pituitary hormones. Increased mitotic activity was noted in 1 lesion (case no. 2), although both cases had high Ki-67 indices (18% and 20%, respectively). The ultrastructural features of both cases were characteristic with intracytoplasmic accumulations of large mitochondria. The histopathologic features of these lesions are consistent with spindle cell oncocytoma of the adenohypophysis. In summary, we are reporting 2 cases of recurrent spindle cell oncocytoma of adenohypophysis with longer follow-up than previously published cases, suggesting the possibility of a more aggressive behavior than has been initially considered.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
9/19. Renal oncocytosis.Renal oncocytosis is a rare disorder in which numerous oncocytic nodules develop in the kidney. An additional case is reported here. The patient was a 51-year-old woman who had received hemodialysis for 27 years. Nineteen years previously she had developed a tumorous lesion in the right kidney, which had been diagnosed as oncocytoma with laparotomic biopsy. Recently the kidney was removed because of enlargement of the tumor. The renal parenchyma was entirely replaced with numerous brownish nodules. Histologically, the nodules were composed of nests of uniform oncocytic cells. Ultrastructurally, the oncocytic cells contained numerous mitochondria. Immunohistochemical features of the nodules were identical to those of sporadic oncocytomas, that is, immunophenotypes similar to the distal nephron and reactivity with antimitochondrial antigen. Based on these findings, the lesion was diagnosed as renal oncocytosis. It was not possible to determine whether the larger nodules should be diagnosed as oncocytoma or a part of oncocytosis. Additionally, the germ line mutation of the Birt-Hogg-Dube (BHD) syndrome gene was examined using the genomic dna obtained from the peripheral lymphocytes, which failed to show any gene alteration. Despite the rare occurrence pathologists and urologists should be aware of renal oncocytosis, as a precursor lesion of renal oncocytoma and chromophobe renal cell carcinoma.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
10/19. Immunophenotypic comparison of salivary gland oncocytoma and metastatic renal cell carcinoma.OBJECTIVES/HYPOTHESIS: The differential diagnosis of oncocytic neoplasms of salivary glands includes both primary and metastatic tumors, one of which is renal cell carcinoma. This study compared immunohistochemical staining characteristics of oncocytomas arising from salivary gland to metastatic renal cell carcinoma using a panel of markers. STUDY DESIGN: immunohistochemistry for cytokeratin 7 (CK7), cytokeratin 20 (CK20), epithelial membrane antigen (EMA), vimentin, CD10, and renal cell carcinoma marker (RCC) was performed on 10 oncocytomas and compared with ten metastatic renal cell carcinomas. RESULTS: There were overlapping histologic findings in the oncocytomas and metastatic renal cell carcinomas, with oncocytomas displaying clear cell changes in 2 of 10 cases. CK7 was positive in 9 of 10 oncocytomas and CK20 in 8 of 10 (7/10 stained for both), and vimentin was only weakly positive in 4 of 10 oncocytomas. All oncocytomas were EMA positive, with membranous staining, and all were negative for CD10 and RCC. Metastatic renal cell carcinoma was strongly positive for vimentin, EMA, and CD10 in most cases. RCC and CK7 were variably positive in metastatic renal cell carcinomas (4/10), and only 1 of 10 showed weak staining with CK20. CONCLUSIONS: Salivary gland oncocytomas and metastatic renal cell carcinomas share some similar histologic and immunohistochemical characteristics. CD10 and CK20 were the most useful markers to distinguish metastatic renal cell carcinoma from oncocytomas in the salivary gland, whereas RCC, EMA, CK7, and vimentin are not as useful.- - - - - - - - - - ranking = 0.16666666666667keywords = antigen (Clic here for more details about this article) |
| | Next -> |