Germinoma with an extensive rhabdoid cell component centered at the corpus callosum.

Intracranial germinomas comprise 0.5-2.0 % of all central nervous system (CNS) tumors and 50-60 % of CNS germ cell tumors. They most frequently originate in the pineal gland and the suprasellar region. The corpus callosum is an extremely uncommon location for germinoma formation. Herein, we report about a 20-year-old man with a germinoma centered at the corpus callosum and that extended to both cerebral hemispheres. In addition to its location, this case is unique in that the amount of tumor cells with rhabdoid morphology exceeded that of tumor cells with typical morphology. The rhabdoid cell component showed an immunophenotype compatible with germinoma. While the presence of rhabdoid cells is generally regarded as a sign of aggressive behavior, the patient has been doing well for at least 4 years since undergoing radiation therapy and chemotherapy. The cellular composition of germinoma might not critically affect prognosis with adequate treatment.

Testicular microlithiasis: what is its association with testicular cancer?

PURPOSE: To determine the prevalence of testicular microlithiasis in patients who were referred for scrotal ultrasonography (US) at a tertiary care cancer center and to evaluate the association between microlithiasis and cancer. MATERIALS AND METHODS: Testicular sonograms obtained in 528 men were retrospectively reviewed to identify patients with US findings suggestive of microlithiasis, intratesticular masses, and intratesticular heterogeneous changes. The association of US findings with medical records and with histopathologic findings that were available in 95 patients was evaluated. Statistical analysis was performed to determine the relationship of testicular cancer, intratesticular mass, and microlithiasis. RESULTS: Forty-eight (9%) of the 528 patients had microlithiasis; 13 of these (27%) had testicular cancers. Of the 480 patients without microlithiasis, 38 (8%) had testicular cancer. Ninety patients had an intratesticular mass, of whom 23 (26%) had microlithiasis. Forty-three (12 with microlithiasis) patients with a mass had testicular cancer, 43 (10 with microlithiasis) had benign findings or nontesticular malignant histopathologic findings, and four (one with microlithiasis) had no pathologic findings. CONCLUSION: Intratesticular microlithiasis is highly associated with confirmed testicular cancer, as well as with US evidence of testicular mass.

Germ cell-like telomeric length homeostasis in nonseminomatous testicular germ cell tumors.

Telomere maintenance plays an important role in cell proliferation and tumor survival. Human male germ cells, which carry long telomeres and express telomerase, give rise to a highly heterogeneous group of malignant tumors. We compared telomeric length and telomerase activity between two major histological types of primary testicular germ cell tumors. Fifteen out of 16 seminoma samples revealed telomeric restriction fragment (TRF) length below 13 kb; the remaining seminoma showed a major TRF fraction of 18 kb and a distinct minor fraction of above 23 kb length. In contrast, all 13 samples from nonseminomas showed TRF length >/=23 kb, which is similar to that reported in human sperm. Nine out of 11 seminoma specimens and six out of seven nonseminomas studied showed moderate to high telomerase activity, the only telomerase-negative nonseminoma being pure mature teratoma. These results indicate to a major difference in telomeric length between seminomas and nonseminomas, which is apparently unrelated to the presence of telomerase activity, and suggest a germline-like homeostasis of telomeric length is preserved in human nonseminomas. Oncogene (2000) 19, 4075 - 4078.

The ultrastructural study of primary intracranial germ tumors.

We describe here ultrastructural and clinicopathological features of five primary intracranial germinomas. By electron microscopy, two major tumor components were defined as large, well differentiated tumor cells and non-neoplastic cells such as macrophages, astrocytes and lymphocytes. Nuclei of tumor cells were round to oval, often presented irregularly contoured nuclear membranes with oval indentations and, occasionally, cytoplasmic invagination. Some of them constituted unusual conformational changes of nuclear membranes rarely described as intranuclear pockets. Desmosome-like intercellular junctions were observed in several neoplastic cells. The nucleoli were composed of a loose, fragmented nucleolonema, whereas elongated, anastomosing and rope-like nucleolonemas, described previously as characteristic for germinomas were not seen. Most tumor cells had villous cytoplasmic projections sometimes intermingled with similar projections of macrophages. Cytoplasm contained a moderate number of mitochondria, a few lysosomes, annulate lamellae, centrioles and glycogen particles. The other distinct components of tumor were lymphocytes, macrophages and astrocytes. Scattered astrocytes typically contained abundant glial filaments adjacent to primary tumor cell. A filopodia-like processes of macrophages often interspersed between other cells, were very prominent features of germinomas. Small lymphocytes were found scattered between the tumor cells, single or in clusters.

The ultrastructural study of primary intracranial germ cell tumours.

We describe here ultrastructural and clinicopathological features of five primary intracranial germinomas. By electron microscopy, two major tumour components were defined as large, well differentiated tumour cells and non-neoplastic cells such as macrophages, astrocytes and lymphocytes. Nuclei of the tumour cells often presented irregularly contoured nuclear membranes with oval indentations and, occasionally, cytoplasmic invagination. Some of them constituted unusual conformational changes of nuclear membranes rarely described as intranuclear pockets. Desmosome-like intercellular junctions were observed in several neoplastic cells. Nucleoli were composed of a loose, fragmented nucleolonema whereas elongated, anastomosing and rope-like nucleolonemas, described previously as characteristic for germinomas were not seen. Typically, the cytoplasm contained glycogen particles. Most tumour cells had villous cytoplasmic projections sometimes intermingled with similar projections of macrophages. Scattered astrocytes typically containing abundant glial filaments were adjacent to primary tumour cells.

Cytologic diagnosis of rhabdomyosarcoma in a patient with germ cell tumor. A case report.

The development of sarcomas in patients with germ cell tumors is rare but has been reported previously. Theories about its pathogenesis include derivation of the tumor cells from pluripotential germ cells and malignant transformation from teratomatous elements. This report describes the occurrence of rhabdomyosarcoma in a patient with a history of mixed germ cell tumor of the testis who developed a malignant pleural effusion. Cytologic evaluation of the fluid revealed single malignant cells with high nuclear/cytoplasmic ratios and prominent nucleoli. While these features initially suggested a diagnosis of metastatic seminoma, careful cytologic and immunohistochemical examination revealed features consistent with metastatic rhabdomyosarcoma. The exfoliative cytologic findings of other germ cell tumors are also discussed.

Expression of the alpha 2-macroglobulin receptor on human neoplastic fibroblastoid cells.

The alpha 2-macroglobulin membrane-associated receptor (alpha 2MR) has been previously detected on hepatocytes, fibroblasts, macrophages, syncytiotrophoblasts and recently on human malignant blood cells of myelomonocytic leukemia. In cells growing in vitro from human germ cell tumors alpha 2MR mRNA was detected by Northern blotting. Endocytosis of alpha 2M from culture medium was detected in these cells by indirect immunofluorescence. In cell extracts alpha 2M and its degradation products were detected by immunoblotting. The cells expressing alpha 2MR and internalizing alpha 2M were identified as fibroblasts both by their morphology and expression of vimentin intermediate filaments. The role and function of alpha 2MR receptor in the analyzed neoplastic cells of teratomatous origin is discussed.

Experimental Sertoli cell tumors in the mouse and their progression into a mixed germ cell-sex cord proliferation.

Males of transgenic families where the large T protein of polyoma virus is expressed in the seminiferous epithelium of the testis (Sertoli and germ cells) develop bilateral testicular tumors when they become old (15 to 18 months). The histological features of these tumors revealed a neoplastic proliferation of Sertoli cell origin. Occasional isolated germ cells arrested at premeiotic stages were seen in the tumor. They did not participate in tumoral proliferation and their malignant character could not at first be established. Tumor cells injected in athymic (nu/nu) mice generated secondary tumors. In this case, a proliferative component of non-Sertoli origin was clearly evident. Its ultrastructural characteristics and the expression of genes that are transcribed in vivo in male germ cells (c-kit, LDH-X, and Hox a-4) suggest the progression of an initial, apparently pure Sertoli cell tumor into a mixed proliferation.