[Sarcoma of the kidney in adults. Apropos of a case].

The authors report a case of renal leiomyosarcoma in a 26-year-old woman, who was treated at the age of 20 for an undifferentiated nasopharyngeal carcinoma. The tumor was very aggressive, with hilar, venous and lymph node involvement. It was not a renal metastasis of the nasopharyngeal carcinoma or renal infiltration by an extrarenal neoplasm. Histological, immunohistochemical and electron microscopy examinations excluded a renal sarcomatoid carcinoma, a Wilms' tumor occurring in adulthood, a clear-cell sarcoma and a peripheral neuroepithelial tumor of kidney.