Monophasic Synovialosarcoma of the Kidney: About a Case and Literature Review

Introduction: Primary renal synovialosarcoma (SVS) is a rare and aggressive disease in which the metastatic potential is very high. Its diagnosis is based on morphological and molecular studies. No therapeutic consensus has yet been established for this histological variant of renal cancer. We describe our experience with a patient followed at the Mohamed IV Center for cancer treatment for primary monophasic synovialosarcoma of the kidney. Case Presentation: In October 2020, a 58-year-old patient with hypertension under treatment, consulted for right back pain without hematuria or calculus emission. The initial examination found a slight right lumbar tenderness. Thoraco-abdominal computed tomography revealed a cystic lesion of the superior pole of the right kidney without secondary lesions. Surgical treatment consisted of an enlarged right total nephrectomy using a bi-subcostal approach. The post-operative consequences were simple. Histologically, it was a poorly differentiated cystic malignant tumor process measuring 17 cm long axis. The limits were healthy as well as the adrenal. Immunohistology made it possible to retain a monophasic synovialosarcoma. However, the patient did not receive genetic analysis. Given the poor prognosis of these tumors, treatment with adjuvant chemotherapy and radiotherapy has been imposed; as indicated in our case. Con-clusion: Primary kidney SVS is a rare, aggressive disease with a poor prognosis. However, the prognosis may be improved by multimodal treatment. A positive diagnosis is difficult and can be confused with other types of renal carcinoma hence the interest in molecular biology.