RESUMEN
A case of primary pharynx synovial sarcoma was reported in this paper. A 15-year-old male patient experienced painless pharyngeal swelling that gradually proliferated for 1 month. Special examination showed an 8 cm × 4 cm × 3 cm tumor located in the left pharynx and the supratonsillar crypt. Imaging tests revealed an irregular mass on the left side of the oropharynx and an unclear boundary. Immunohistochemical examination yielded the following results: epithelial membrane antigen (+), cytokeratin (CK)19 (+), CD7(+), vimentin (+), CK10(-), E-cadherin (+), B-cell lymphoma-2 (-), CD2 (-), CD10 (-), CD138 (+), CD99 (+), leukocyte common antigen (+), and Ki-67 (20%+). This condition was pathologically diagnosed as primary pharynx synovial sarcoma.