Synovial Sarcoma of the Infratemporal Fossa With Extension Into the Oral Cavity—A Rare Presentation and Literature Review

Abstract

Synovial sarcoma (SS) is a relatively rare malignancy primarily affecting the lower extremities of young males. It is considered the fourth most common type of sarcoma after fibrous histosarcoma, liposarcoma, and rhabdomyosarcoma. 1 Notably, 3% to 10% of all synovial sarcomas occur in the head and neck region, with the hypopharynx and cervical lymph nodes the most common sites. The origin of SS is unknown, but it is thought to arise from primitive, undifferentiated, pluripotent mesenchymal cells of the parasynovial tissue. Owing to its uncommon occurrence and its unique histopathologic features, it is often misdiagnosed. There is a definitive need to report the cases of synovial sarcoma as and when diagnosed, because knowledge about the diagnosis, clinical behavior, management strategies, and prognosis is still lacking. Several reports of SS occurring in the head and neck region (eg, paranasal sinuses, larynx, hypopharynx, parotid gland, orofacial region, and retropharyngeal space) have been described. 1-15 However, there are only a few reports of SSs occurring in the infratemporal fossa (ITF). 16-18 To our knowledge, this is the first reported case of SS of the right ITF with extension of the tumor into the oral cavity causing severe trismus and obstruction of the entire oral cavity in an Asian Indian population. We discuss the related diagnostic and therapeutic aspects.