Primary renal synovial sarcoma: computed tomography imaging findings

Background:A synovial sarcoma arising from the kidney is extremely rare. To date, few data are available on their radiological features.Purpose:To identify the computer tomography (CT) imaging findings of primary renal synovial sarcomas (PRSSs).Material and Methods:Five cases of PRSS confirmed by histopathological and cytogenetic studies were retrospectively analyzed. All patients had undergone unenhanced and multiphase enhanced CT examinations (one patient underwent CT twice). The CT characteristics, including shape, size, margin, attenuation, and enhancement pattern after intravenous contrast medium injection, were analyzed.Results:The study involved two female and three male patients (mean age, 27.4 years; range, 15–43 years). Unenhanced CT showed completely or partly well-defined masses, with heterogeneous (n = 5) or homogeneous (n = 1) patchy low density. On multiphase contrast-enhanced CT, in five of the six CT examinations, the tumors appeared as solid-cystic masses with cyst walls or pseudo-capsul...