Monophasic synovial sarcoma of the tongue in an elderly lady: A diagnostic dilemma

Synovial sarcoma (SS) is a morphologically characteristic sarcoma of uncertain lineage, typically containing both epithelial and mesenchymal elements. The most common location is the extremities, and very few cases have been reported from the head and neck region. The monophasic spindle cell variant often poses a diagnostic challenge as it mimics poorly differentiated carcinoma or sarcoma. We report a case of monophasic SS of tongue in a 74-year-old female. On Immunohistochemistry, the tumor cells showed strong, diffuse positivity for vimentin, Bcl-2, CD99, and focal positivity for epithelial membrane antigen. Tumor cells were negative for pan cytokeratin, smooth muscle actin, S100, HMB-45, CD34. A high index of clinical suscipicion is required to reach an accurate diagnosis for institution of appropriate therapy.