1/78. Microcystic meningioma arising in a mixed germ cell tumor of the testis: a case report.We report a case of a microcystic variant of meningioma arising in a mixed germ cell tumor of the testis composed predominantly of mature and immature teratoma with elements of seminoma and embryonal carcinoma. We believe this is the first such case of a meningioma arising in a teratoma within a gonadal or extragonadal site. The meningiomatous component showed positive immunohistochemical staining for epithelial membrane antigen and a lack of staining for cytokeratin, factor viii, CD31, and alpha-fetoprotein. Recognition of a non-germ cell tumor arising in the setting of a teratoma in the testis may be prognostically important depending on the nature of the non-germ cell component and whether it has spread beyond the testis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/78. Interdigitating dendritic cell tumor of the testis: a novel testicular spindle cell neoplasm.Interdigitating dendritic cell tumor is an extremely rare neoplasm that mainly occurs in lymph nodes. An example of such a tumor in the testis, a hitherto unreported site, is described. Grossly, the tumor was light tan with a uniform solid appearance, replacing virtually the entire testis. Microscopically, it was formed by whorls and fascicles of spindle cells intermingling with small lymphocytes. Such a histologic appearance can, however, mimic a wide variety of other tumors and tumor-like lesions, among which mesenchymal sarcoma, spindle cell carcinoma, follicular dendritic cell tumor, and inflammatory pseudotumor are the main differential diagnoses. Immunohistochemical studies showed that the spindle tumor cells were strongly and diffusely positive for S-100 protein and vimentin. They were also focally positive for CD68 and CD4, but were uniformly negative for leukocyte common antigen, CD1a, CD3, CD20, CD21, CD23, CD34, CD35, actin, desmin, HMB45, cytokeratins, and placental alkaline phosphatase. Ultrastructurally, the tumor cells possessed complex interdigitating cytoplasmic dendritic processes, with abundant rough endoplasmic reticulum and mitochondria in their cytoplasm. An in situ hybridization study for Epstein-Barr virus was negative. The pathologist should be aware of such an entity and consider it in the list of differential diagnoses for unusual spindle cell lesions with a significant background population of small lymphocytes. However, because of its nonspecific histologic appearance, additional immunohistochemical and electron microscopic studies are generally required for its definitive diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/78. rhabdomyosarcoma metastasizing as a malignant ectomesenchymoma.rhabdomyosarcoma is a common childhood malignancy that may occasionally occur as a component of a mixed mesenchymal tumor, e.g., a triton tumor or malignant ectomesenchymoma. A case is reported of a 13-year-old boy who had resection of a paratesticular embryonal rhabdomyosarcoma with subsequent radiation and chemotherapy. Two years later, a retroperitoneal metastasis was resected. histology showed a mixture of rhabdomyoblasts, ganglion cells, and a third population of cells with combined features of these two distinct cell types. Electron microscopy confirmed the presence of rhabdomyoblasts with characteristic bundles of myofilaments and Z-band material, and ganglion cells with prominent nuclei and nucleoli, rough endoplasmic reticulum, dense core granules, filaments, and tubules. Notably, the third cell population showed features of both rhabdomyoblasts and ganglion cells. immunohistochemistry confirmed the mixed population of rhabdomyoblasts (positive for vimentin, desmin, negative for S-100, NSE), ganglion cells (positive for S-100 and NSE, negative for vimentin and desmin), and the third population expressing all test antigens. The features of this metastatic lesion are those of a malignant ectomesenchymoma with combined rhabdomyosarcoma and ganglioneuroma components. It is postulated that this lesion results from biphenotypic expression of tumor cells that previously expressed only rhabdomyoblastic differentiation. The role of prior chemotherapy and radiotherapy in this particular case is unclear.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/78. Hepatoid variant of yolk sac tumor of the testis.A case of testicular yolk sac tumor (endodermal sinus tumor) consisting predominantly of hepatoid cells is documented. A mass measuring approximately 4 x 3 cm was noted in the left testis of a 64-year-old man. Preoperative examination revealed an elevated serum level of alpha-fetoprotein (5479 ng/mL). Histologically, the lesion was composed predominantly of sheet-like or trabecular proliferation of hepatocyte-like cells with eosinophilic or clear cytoplasm. The tumor cells were immunoreactive for alpha-fetoprotein, antimitochondrial antibody, cytokeratin (AE1/AE3), alpha-1-antichymotrypsin, alpha-1-antitrypsin, albumin, carcinoembryonic antigen and epithelial membrane antigen. It was necessary to distinguish this variant lesion from metastatic hepatocellular carcinoma, embryonal carcinoma and hepatoid carcinoma.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
5/78. Tubulocystic clear cell adenocarcinoma arising within the prostate.neoplasms resembling ovarian common epithelial-type tumors, including clear cell adenocarcinomas, rarely occur in the lower urinary tract of men. When they do, they develop in the urethra or urinary bladder. We report a case of such a tumor arising within the prostate of a 47-year-old man. The tumor was a cystic mass in the left posterolateral region of the prostate. Histologically, the tumor was chiefly composed of tubulocystic and papillary glands lined by glycogen-rich, cuboidal or hobnail cells with clear to eosinophilic cytoplasm. The tumor cells were strongly positive for pan-cytokeratin, low molecular weight cytokeratin, and epithelial membrane antigen, and focally positive for high molecular weight keratin. The tumor did not immunohistochemically express prostate-specific antigen (PSA) and prostatic acid phosphatase. Serologically, the patient had increased levels of CA125 instead of PSA. The clinical as well as the pathologic features are consistent with a clear cell adenocarcinoma as seen in the female genital tract rather than a typical prostatic adenocarcinoma.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/78. Nonhepatosplenic gamma delta T-cell lymphoma with initial testicular compromise.We report here a case of nonhepatosplenic gammadelta T-cell lymphoma with undescribed initial localization in testis, without hepatosplenomegaly or adenopathies, and subsequent development in the maxillary sinus. The maxillar mass biopsy revealed a T-cell infiltration, and its immunologic characterization by flow cytometry showed a gammadelta T-cell phenotype (CD45 , CD3 , CD2 , TCR gammadelta ), without expression of CD7, CD5, CD1a, TdT, CD4, CD8, TCR alphabeta, or NK antigens (CD16, CD56, and CD57). Clonal gamma-chain gene rearrangement by polymerase chain reaction (PCR) was detected in testicular and maxillar biopsies. Epstein-Barr virus type 1 (EBV) sequences were detected by molecular biology in the biopsy material, suggesting that this oncogenic virus may play a role in the genesis of the clonal expansion of gammadelta T-cells. The patient was initially treated with standard chemotherapeutic protocols, with poor response and aggressive course.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/78. Ongoing hypermutation in the Ig V(D)J gene segments and c-myc proto-oncogene of an AIDS lymphoma segregates with neoplastic B cells at different sites: implications for clonal evolution.To investigate the role of somatic Ig hypermutation in the evolution of AIDS-associated B cell lymphomas, we analyzed the Ig V(D)J and c-myc genes expressed by neoplastic B cells in two extranodal sites, testis and orbit, and clonally related cells in the bone marrow. testis and orbit B cells expressed differentially mutated but collinear V(H)DJ(H), V kappa J kappa and c-myc gene sequences. Shared mutations accounted for 10.2%, 8.4%, and 4.3% of the overall V(H)DJ(H), V kappa J kappa, and c-myc gene sequences. Tumor-site specific V(H)DJ(H), V kappa J kappa, and c-myc mutations were comparable in frequency, and a single point-mutation gave rise to an EcoRI site in the testis c-myc dna. Both shared and tumor site-specific V(H)DJ(H), V kappa J kappa, and c-myc mutations displayed predominance of transitions over transversions. The "neoplastic" V(H)DJ(H) sequence was expressed by about 10(-5) cells in the bone marrow, and contained two of the three orbital, but none of the testicular V(H)DJ(H) mutations. The nature and distribution of the Ig V(D)J mutations found in the kappa chain suggested a selection by antigen in testis and orbit. Our data suggest that, in AIDS-associated B cell lymphomas, the Ig hypermutation machinery targets V(H)DJ(H), V kappa J kappa, and c-myc genes with comparable efficiency and modalities.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/78. Primary follicular large cell lymphoma of the testis in a child.Primary follicular lymphoma of the testis in childhood is extremely rare. To our knowledge, only 5 cases have been reported to date. We report a case in a 6-year-old boy who presented with painless right scrotal enlargement. Right radical orchiectomy revealed a follicular large cell lymphoma with diffuse areas confined to the testis and epididymis, clinical stage IE. Immunohistochemical stains demonstrated that the neoplastic cells were of B-cell lineage, positive for CD10, CD20, CD79a, and BCL-6. Staining for CD21 accentuated networks of dendritic reticulum cells within the nodules. The cells were negative for BCL-2, p53, and T-cell antigens. There was no evidence of the t(14;18) detected by polymerase chain reaction. The data suggest that follicular lymphoma of the testis in children has a different pathogenesis than follicular lymphoma in adults.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/78. Deletion 5p11 accompanied by multiple numerical changes in testicular lymphoma.We describe a case of testicular B cell lymphoma with deletion of chromosome 5, del(5)(p11), as a sole structural abnormality. Histopathological diagnosis of the tumor was a high-grade lymphoma of the diffuse type containing cells positive for B cell specific antigen (CD20) and negative for the leukocyte common antigen (CD45). Deletion 5p may define the region of a tumor suppressor gene that could be associated with tumor progression and invasiveness and may serve as an indicator of poor prognosis in testicular lymphomas.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
10/78. PET and PLAP in suspected testicular cancer relapse: beware sarcoidosis.A 31-year-old man previously treated with chemotherapy for metastatic testicular cancer presented with new mediastinal lymphadenopathy and peripheral lung opacities. serum tumour markers were not elevated and a PET (positron emission tomography) scan revealed increased FDG (fluoro-deoxyglucose) uptake in the lungs and mediastinum consistent with testis cancer relapse. A biopsy of a mediastinal lymph node was performed and the pathology was that of sarcoidosis. immunohistochemistry however was positive for PLAP (placental alkaline phosphatase) and negative for EMA (epithelial membrane antigen). This immunohistochemical profile raised concerns that the observed pathology represented a sarcoid reaction to micro-metastatic testicular cancer relapse. We performed immunohistochemical pathology analysis on four known cases of sarcoidosis and found the same immunohistochemical-staining pattern. This case highlights the problem of specificity when interpreting the significance of PET scans and immunohistochemical analysis in this situation. sarcoidosis, a condition that has been associated with testicular cancer, should always be considered in the differential diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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