[Primitive renal synovial sarcoma: a cystic tumor in young patients]

The study of the clinical, histological and immunohistochemical aspects of three kidney tumors corresponding to synovial sarcomas operated on in our center over three years.

Three patients aged between 27 and 33 had an enlarged nephrectomy for kidney tumors corresponding to a histological examination of a synovial sarcoma. The tumors were symptomatic in 100% of cases with back pain and spontaneous rupture. Size varied from 5 to 13cm. The radiological aspect was a cystic tumor (BosniakIV) in two cases and in the other a spontaneous perirenal hematoma. Two were in the right kidney and one in the left kidney. The parts were analyzed after fixation. Immunohistochemical coloration and an analysis in molecular biology by RT-PCR of fusion transcripts were carried out.

One patient died because of local development and metastasis 24 months after an enlarged nephrectomy associated with radio chemotherapy (Maidprotocol). Two patients were in total remission after an average of 25 months following the same treatment. The histology found a mesenchymal fusocellular monotone proliferation corresponding to a sarcoma. In all three cases, it was a biphasic form with plaques of fusiform cells and epithelial cells. The immunohistochemical study shows a positivity of the contingent epithelial and fusiform. The muscular markers were negative. A study in molecular biology of the fusion transcript allowed for the finding of a translocation (X;18) in all three cases.

Primitive synovial sarcoma of the kidney occured in young patients. The translocation (X;18) is pathognomonic of the diagnosis. The prognosis is bleak despite complete excision, radiotherapy and chemotherapy.