Biphasic Synovial Sarcoma in a 12-Year-Old Boy with Prominent Glandular Features: Case Report and Review of the Literature

Abstract

Synovial sarcoma (SS) is an uncommon tumor of the soft tissue. The etiology of this tumor is mainly unknown. The name "synovial sarcoma" is misleading, as it has no connection with the synovium despite occurring mostly juxta-articular. The tumor does not arise from or differentiate toward synovium. Due to the rarity of SS, a definitive diagnosis can be challenging. One variant of SS is biphasic synovial sarcoma (BSS). This type of SS displays a dual-cell population, which can lead to incorrect diagnosis when sampling is inadequate. We present a case of a 12-year-old boy who presented with biphasic synovial sarcoma confirmed by molecular testing and misdiagnosed as a malignant adnexal skin tumor. BSS is uncommon and can be confused with other benign and malignant soft tissue tumors. A correct diagnosis of SS is significant as early studies of the utility of targeted medicine and T cell receptor-based immunotherapy are promising for clinical use. We also reviewed the pertinent literature, including differential diagnosis, pathology, recent immunohistochemical and genetic findings, management, and prognosis.