[Primary renal angiosarcoma]. / Angiosarcoma renal primario.

The twenty-fourth case of primary renal angiosarcoma is described, according to the available international literature, this present in a 71-year-old male, a mechanic by trade, without carcinogenic antecedents. Hematuria, pain in flank, and left-side tumoral mass of approximately 20 cm in diameter located in kidney by computerized axial tomography (CT) constituted manifestations. A left nefrectomy was performed. No metastasis was found. The tumor replaced 4/5 of the organ and weighed 1145 g. It showed angiomatous structure with atypical proliferation of endothelial cells in a sinusoldal trauma and anastomosatic vascular channels that invaded neighboring parenchymal and capsule. Tymorous cells were positive for CD31 and CD34 and negative for cytokeratins, S100 and HMB 45 proteins. The patient was subjected to treatment with chemotherapy and radiotherapy (lineal accelerator), but 12 months after surgery he presented retroperitonal tumoral relapse and hepatic metastasis. Diagnostic differentiation with benign vascular tumors is pointed out, as well as carcinomas and sarcomas that showed an outstanding angiomatous component, both primary and/or secondary. Primary renal angiosarcoma exposes the multiplicity of localizations that it is capable of with a tumor of this type, as well as renal parenquimatous capacity to be the seat of a great variety of neoplasias.

[Extraovarian sex cord mesenchymatose tumor]. / Tumor mesenquimatoso extraovárico del cordón sexual.

A 32-year-old female presented with a large tumoral mass in the left upper quadrant (ULQ) of the abdomen with abdominal and retroperitoneal components, infiltrating the spleen and adhered to pancreatic tail, colon, left kidney, and stomach that could be completely resected along with the spleen. Histopathologic study including immunohistochemical profile was coincident with results obtained at Barnes-Jewish Hospital of Washington University Medical Center, USA. This study showed areas of granulosa tumor cells as well as thecal features of fusiform cells with eosinophilic cytoplasm and tubular formations corresponding to Sertoli cells. According with embryologic development, the specialized stroma of the genital crest is induced to proliferase after primordial germ cells infiltrate the crest; in this way, tumoral growth can occur at any site along this migration. The predominating localization of this unique ectopic tumor coincides with the descending route of the ovaries or its components. This case, included in unclassified forms of stromal sex cord tumors, is considered a monodermal malignant teratoma. Is was the second tumor of retroperitoneal localization and the eleventh ectopic, according to the world literature reviewed.