1/28. 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 = nature (Clic here for more details about this article) |
2/28. Embryonal sarcoma of adult and pediatric kidneys: report of a case with localized submucosal invasion of the renal pelvis and long-term survival.A case of cystic embryonal sarcoma of the kidney (CESK) with a rapidly fatal outcome was recently reported.1 Here, we report another case of a 12-year-old boy with a localized but ill-defined submucosal lesion of CESK in the right renal pelvis. The tumor consisted principally of small mesenchymal cells with oval to spindle nuclei and scanty cytoplasm, infiltrating in dense arrangements. Two growth patterns were distinguished in the tumor cells: (i) a diffuse infiltrating pattern without an epithelial component; and (ii) a foliated pattern with an epithelial lining over the surface. Foci of the diffuse pattern predominated over those that were lobular, infiltrating superficial layers of renal sinuses and along pyramids, in both of which remarkable intravenous invasion was evident. Foci of the foliated pattern invaded deeper portions of a few sinuses and frequently penetrated into their veins, producing together with their epithelial lining a characteristic foliated structure. Lining epithelial cells around lobular foci often appeared hob-nailed or eosinophilic in the cytoplasm. Despite the remarkable intravenous encroachment, the patient has remained well without a recurrence for more than 26 years after a simple nephrectomy. The present case report expands our understanding of the biological nature of CESK.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/28. Clear cell sarcoma of the kidney with invasion of the inferior vena cava.OBJECTIVE: We present a case of clear cell sarcoma of the kidney (CCSK) in 53-year-old white man who was treated with surgery. This case represents the oldest patient with CCSK published in the English literature. methods: Right radical nephrectomy with lymphadenectomy and thrombectomy was performed. RESULTS: Histological findings indicated a CCSK. Tumor cells showed positive vimentin staining. CONCLUSION: CCSK is considered a rare and highly malignant renal tumor. The malignant nature may relate not only to the biological features of these tumor cells, but also to the high resistance against radiation and chemotherapy. The treatment of CCSK has been a subject of controversy.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/28. Melanotic cerebral ganglioglioma: evidence for melanogenesis in neoplastic astrocytes.A composite melanotic glial-ganglionic tumor was resected from a 17-year-old girl who presented with a 5-year history of epilepsy. Grossly, the tumor was partly cystic, partly solid, located superficially in the temporal lobe. Histologically, its glial component was composed of spindle and pleomorphic cells, including tumor giant cells, which were associated with Rosenthal fibers, eosinophilic granular bodies and marked desmoplasia. The cells had immunohistochemical and ultrastructural features of astrocytes, and some were invested by incomplete basal lamina. Thus, the tumor had many features in common with pleomorphic xanthoastrocytoma. However, its most striking feature was the presence of melanin pigment in numerous neoplastic cells. Immunoelectron microscopy revealed glial fibrillary acidic protein-positive intermediate filaments in tumor cells bearing melanosomes and premelanosome, proving their astrocytic nature. This case demonstrates, for the first time, melanosomal melanogenesis in human cells with astrocytic phenotype, and provides additional evidence for the ability of central neuroepithelial cell derivatives to produce melanin.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/28. pulmonary blastoma with a topographic transition from blastic to more differentiated areas. An immunohistochemical assessment of its embryonic nature using stage-specific embryonic antigens.In order to investigate the probable embryonic nature of pulmonary blastoma, immunohistochemical studies were performed using stage-specific embryonic antigens (Ley, Lex, sialyl Lex-i) in case of pulmonary blastoma with a very wide spectrum of morphological features. The tumour presented a topographic transition from primitive blastic and embryonic areas to more differentiated areas showing diverse differentiation. Blastic areas composed of extremely immature cells were found in most peripheral parts of the tumour. Inside the blastic areas there were "embryonic" areas which morphologically resembled human embryo lungs in the pseudoglandular and canalicular stages. Most central parts of the tumour showed more differentiated features including chondrosarcomatous, leiomyosarcomatous and rhabdomyosarcomatous elements and the common type of adenocarcinomatous element. Electron microscopic observation suggested the blastic and embryonic nature of these immature cell elements. Ley was expressed in the blastic and pseudoglandular areas. Lex was expressed in the canalicular areas. These antigens were not expressed in the more differentiated areas. The topographic gradient in the tumour of morphology and antigen expression from the peripheral blastic areas to the central more differentiated areas suggests that the primitive cells gradually differentiated into more mature cells of various directions as the tumour grew in size.- - - - - - - - - - ranking = 6keywords = nature (Clic here for more details about this article) |
6/28. Cerebral hemiatrophy with superficial siderosis and PLEDs due to a germ cell tumor of the basal ganglia.The diagnosis of basal ganglia germ cell tumors may be delayed due to slow progression and minimal early changes on magnetic resonance imaging (MRI). The cystic nature of some tumors may lead to non-diagnostic biopsies. We describe the clinical, imaging, laboratory, and postmortem findings of a basal ganglia germ cell tumor in a 19-year-old man. Clues to an early antemortem diagnosis based on MRI findings and determination of tumor markers are discussed. An early diagnosis and accurate characterization of basal ganglia germ cell tumors is essential for optimal therapy. The presence of cerebral hemiatrophy and hemorrhagic or cystic components is suggestive. Measurement of serum and cerebrospinal fluid markers such as human chorionic gonadotropin may suggest the diagnosis.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/28. Malignant mixed mullerian tumor of the ovary. Report of a case studied by immunohistochemistry.A case of malignant mixed mullerian tumor of the ovary in a 57-year-old woman is reported along with the results of an immunohistochemical study. The tumor, measuring 16 x 10 x 9 cm, was composed predominantly of adenocarcinoma with a smaller amount of anaplastic carcinoma as an epithelial component and chondrosarcoma, liposarcoma, fibrosarcoma and rhabdomyoblasts as mesenchymal elements. immunohistochemistry using paraffin sections demonstrated cytokeratin (CK) and epithelial membrane antigen (EMA), generally regarded as epithelial markers, not only in the epithelial component but also in chondrosarcoma cells. vimentin and desmin, generally regarded as mesenchymal markers, were exhibited partly in carcinoma cells as well as in mesenchymal elements. Positive staining for S-100 protein was obtained not only in chondrosarcoma and liposarcoma cells, but also partly in adenocarcinoma cells. This intricate immunohistochemical picture reflected the histologic findings. It is noteworthy that both carcinoma cells and chondrosarcoma cells demonstrated simultaneous expression of CK, EMA, vimentin, desmin and S-100 protein. This somewhat unusual antigen expression by tumor cells may indicate a change in the nature of tumor cells due to microenvironmental factors.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/28. Cytokeratin expression in a congenital multipotential primitive neuroectodermal tumor.A case of an uncommon congenital primitive neuroectodermal cerebellar tumor (PNET) in a 5-month-old child is reported. After subtotal surgical resection, the residual tumor did not respond to radiation and chemotherapy. Histologically, the tumor was composed of small, round, undifferentiated cells and several other patterns like astrocytomatous, oligodendrogliomatous, and ependymomatous structures. Immunostaining was positive for most of the cells for vimentin and S 100, fewer were positive for glial fibrillary acid protein (GFAP) and neuron-specific enolase, and only a few for synaptophysin. Surprisingly, the tumor showed strong expression of several monoclonal cytokeratins (CK) with different molecular weights, together with epithelial membrane antigen. Furthermore, we found a coexpression of the tumor cells for CK and vimentin, while CK-GFAP and CK-S 100 were negative. Ultrastructurally, intracytoplasmic intermediate filaments could be observed corresponding to immunohistochemical CK expression. The very strong CK and vimentin expression in this case was interpreted as a sign of the embryonic nature of the tumor.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
9/28. Malignant mixed tumor of the liver: report of a case and a review of the literature.Malignant mixed tumor of the liver seen in a 4 year old girl was reported. Progressive hepatomegaly, jaundice, anemia, and extraordinarily high level of serum total cholesterol were noted clinically. Postmortem examination had disclosed that most part of the tumor was occupied by fibrosarcomatous cell growth admixed with rhabdomyosarcomatous component. In addition, carcinomatous component was distinctly recognized in a restricted part of the liver tumor. Previous reports on malignant mixed tumor of the liver were reviewed and it was emphasized that the histological diagnosis of malignant hepatic mixed tumor must be cautiously followed Edmondson's criteria; which requires existence of both epithelial and mesenchymal components of neoplastic nature and malignancy of either or both components in a hepatic tumor.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
10/28. endodermal sinus tumor of the anterior mediastinum.An endodermal sinus tumor presenting as a lobulated anterior mediastinal mass in a 20-year-old white man is reported. The clinical implications, histology, and origin of this rare germ cell tumor are discussed. The invasive nature of this highly malignant neoplasm prevented complete surgical resection.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
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