Sarcoma sinovial renal en edad temprana

objective: we report a primary renal synovial sarcoma (ss) case and analyze its features. method: a 15 year old male presented with left abdominal mass and weight loss. ct scan images showed a 13 cm mass located in the lower pole of the left kidney. renal biopsy recognized an undifferentiated neoplasm, the immunohistochemistry suggesting the probability of neuroectodermic primitive tumor versus ss. chemotherapy and radical nephrectomy were carried out. pathological study showed a big multilobulated necrotic tumor 22x13x12.5 cm. histopathological study demonstrated a neoplasm composed by immature cells. currently, patient has survived 1,8 years. a structured bibliographical search was performed in the medline, imbiomed and scielo databases. results: the final immunohistochemistry studies gave the diagnosis of poorly differentiated renal ss small cell variety. conclusion: the renal ss is extremely infrequent, with less than 40 cases reported, of which this case reports the earlier age. these tumors, when located in the kidney, represent a great diagnostic challenge that requires adequate clinical, radiological, surgical, and pathological correlation for appropriate diagnosis and treatment.