Primary renal synovial sarcoma with negative immunohistochemistry: a case report and literature review

Just less than 200 cases of primary renal synovial sarcoma (PRSS) are known, a very rare neoplasm of the kidney. The diagnosis can be very challenging because of its similarity with other neoplasms, and is based on anatomopathological analyses, especially immunohistochemistry and cytogenetics. Due to the rarity, there are no standard protocols for treatment, although radical nephrectomy is considered the primary treatment and can be associated or not with chemotherapy. We present a case of PRSS with negative immunohistochemistry: the importance of both methods for a correct diagnosis is underlined, and a literature review of this rare entity is presented.