Ovarian malignant mixed mesodermal tumor with neuroectodermal differentiation: a multifaceted evaluation.

Malignant mixed mesodermal tumors (MMMTs) of the ovary are rare, highly aggressive neoplasms that arise most commonly in postmenopausal women. Histologically, they consist of a mixed population of malignant epithelial and mesenchymal elements. Neuroectodermal differentiation in ovarian MMMTs is exceedingly uncommon, with only a few case reports in the literature. We present a case of an ovarian MMMT with neuroectodermal differentiation in a 78-year-old female patient. Histologically, the tumor was composed of epithelial, mesenchymal, and neuroectodermal elements. The neuroectodermal component was predominantly that of a medulloepithelioma, with scattered areas displaying features of an anaplastic astrocytoma, including rare ganglion cell differentiation. The neuroectodermal component showed immunoreactivity for glial fibrillary acidic protein, synaptophysin, and S100 protein. Ultrastructurally, the neuroectodermal component was populated by cells with irregular nuclei, finely dispersed chromatin, rudimentary cell junctions, and a delicate basement membrane, all of which have been described in medulloepitheliomas. DNA ploidy analysis was also performed on the various components of the tumor and compared with 3 additional cases of MMMT without neuroectodermal differentiation and 2 ovarian immature teratomas. Our findings suggest that the neuroectodermal component may arise from a separate clone or at least evolves at an earlier stage of tumor development.

Primary heterologous carcinosarcoma (metaplastic carcinoma) of the urinary bladder: a clinicopathologic, immunohistochemical, and ultrastructural analysis of eight cases and a review of the literature.

BACKGROUND: Heterologous carcinosarcomas of the urinary bladder are rare neoplasms, the histogenesis of which is still disputed. METHODS: The clinicopathologic, immunohistochemical, and ultrastructural features of eight cases were analyzed. RESULTS: The patients, 5 males and 3 females, had a median age of 70 years. Gross hematuria, dysuria, and urinary tract infections were the main presenting symptoms. Tumors were solitary in all cases and located in the right wall in six cases. Tumor size ranged from 2 to 12 cm (median, 5 cm). Four patients died of disease 2, 6, 17, and 42 months postoperatively, respectively. Microscopically, the tumors consisted mostly of a varied mixture of high grade transitional cell carcinoma with chondrosarcoma, osteosarcoma, rhabdomyosarcoma, and undifferentiated spindle cell (leiomyosarcoma-like) components with occasional transitional features between one component and another. All tumors but one invaded the muscularis propria or the perivesical fatty tissue. Immunohistochemically, keratin expression was observed focally in the sarcoma component as well as the carcinoma component. Reactivity for vimentin, desmin, muscle specific actin, and S-100 protein was observed in poorly differentiated areas in addition to the expected positivity of each histologic subtype of sarcoma. Ultrastructurally, one tumor showed evidence of both epithelial and chondrosarcomatous differentiation, whereas three contained rhabdomyosarcomatous elements. CONCLUSIONS: On the basis of the current series and a review of 55 reports from the literature, primary heterologous carcinosarcoma of the urinary bladder proved to be a highly malignant type of neoplasm occurring predominantly in elderly males that was most often in an advanced stage at presentation and rapidly became lethal. Histogenetically, some heterologous carcinosarcomas should be regarded as a variant of sarcomatoid carcinoma (metaplastic carcinoma) that shows prominent heterologous differentiation.