BACKGROUND:

Synovial sarcoma is an infrequent neoplasia and is the fourth most common type of sarcoma. It is often situated in the para-articular region of the lower limbs and tendons. Its renal location is more common in patients 15-40 years of age, with a mean of 38 years. It is predominant in the male sex and manifests as a sensation of abdominal mass, hematuria, and nonspecific signs.

CLINICAL CASE:

A 59-year-old woman sought medical attention for pain in the right lumbar region, plus emesis and hematuria, accompanied by a palpable, hard, painless mass in the right upper quadrant. A computerized tomography scan revealed an enlarged right kidney with dense, heterogeneous components. Right nephrectomy was performed. The pathology report stated synovial sarcoma diagnosis that was confirmed by immunohistochemistry. Finally, the patient died due to a recurrent tumor involving the right renal fossa.

CONCLUSIONS:

Synovial sarcoma is a rare entity with a special predilection for certain anatomic zones. Renal location is exceptional and there are presently few reported cases in the literature. It is an aggressive tumor with a poor treatment response, resulting in a high morbidity and mortality rate.