Synovial sarcomas, which represent approximately 10% of all soft tissue sarcomas, are aggressive spindle cell sarcomas containing in some cases areas of epithelial differentiation. They consistently show a specific t(X;18)(p11.2;q11.2), which usually represents either of 2 gene fusions, ... Synovial sarcomas, which represent approximately 10% of all soft tissue sarcomas, are aggressive spindle cell sarcomas containing in some cases areas of epithelial differentiation. They consistently show a specific t(X;18)(p11.2;q11.2), which usually represents either of 2 gene fusions, SYT (600192)-SSX1 (312820) or SYT-SSX2 (300192), encoding putative transcriptional proteins differing at 13 amino acid positions (summary by Ladanyi et al., 2002). Synovial sarcoma, according to the experience of Enzinger and Weiss (1983), is the fourth most common type of soft tissue sarcoma. It usually develops in adolescents and young adults, is more common in males than in females, and has no racial predilection.
The patient described by Griffin and Emanuel (1987) was a 12-year-old black female with an unremarkable previous medical history, who presented with a 3-month history of right calf pain and swelling following a fall onto the right leg. ... The patient described by Griffin and Emanuel (1987) was a 12-year-old black female with an unremarkable previous medical history, who presented with a 3-month history of right calf pain and swelling following a fall onto the right leg. Physical examination was unremarkable except for a large palpable mass in the posterior aspect of the right lower leg. Biopsy of the mass, performed to rule out hematoma, showed a spindle cell soft tissue malignancy, probably monophasic synovial sarcoma. CT scan of the leg showed that the mass encompassed more than one-half of the soft tissue of the leg. No metastasis was detected. An above-the-knee amputation was performed. Ueda et al. (1988) studied a 13-year old Japanese girl with synovial sarcoma who presented with a very large (15 x 12 cm), hard mass on her right buttock. She had no personal or family history of malignancy. After resection of the tumor, adjuvant chemotherapy was administered. Metastasis to the lung had occurred. Histologically the tumor was composed mainly of solidly packed plump oval or short-spindle cells with a pronounced hemangiopericytomatous pattern and a small portion of pseudoglandular or epithelial arrangement. Tumor cells showed the translocation t(X;18)(p11.2;q11.2). Synovial sarcoma is an uncommon soft tissue sarcoma that usually occurs in adolescents and young adults. Histologically, synovial sarcoma shows 2 patterns of proliferation: biphasic pattern and monophasic pattern. In the former type, it is easy to make a definite diagnosis. It is difficult and sometimes impossible to distinguish clearly monophasic synovial sarcoma from fibrosarcoma or malignant Schwannoma by routine histology alone. Immunoperoxidase procedures provide a convincing clue to differentiate these conditions; the positive staining of plump cells by anti-human keratin sera is sufficiently characteristic to make a diagnosis of synovial sarcoma (summary by Ueda et al., 1988).