オトガイ部に生じた滑膜肉腫の１例

Abstract

A case of synovial sarcoma of the mental region is reported. The patient was a 38-year-old man with swelling and tenderness of the right mental region. The pathological diagnosis of a biopsy specimen was “sarcoma”, and the tumor was resected radically with the skin, muscle, and cortical bone of the mandible. Microscopic examination of the tumor showed dominant atypical spindle cells distributed in bands and a few slit-like structures lined by epithelioid cells. Immunohistochemical studies showed epithelial membrane antigen (EMA) and keratin positive sites in part of the slit-like structures. The spindle cells were vimentin positive. Ultrastructural findings revealed microvilli and desmosomes. Based on these findings, the pathological diagnosis of this tumor was synovial sarcoma (monophasic fibrous type). There have been no symptoms or clinical signs of recurrence or metastasis as of 21 months after the operation.