口腔底に発生したmyopericytomaの1例

A case of myopericytoma of the floor of the mouth

I．はじめに

　Myopericytoma（筋周皮腫）は，2002年の新WHO分類^1）▲で新たに取り上げられた腫瘍で，perivascular tumorに分類されている。四肢遠位部に好発する良性腫瘍であるが，頭頸部領域ではこれまでに報告例がない。今回われわれは，口腔底に発生したmyopericytomaの1例を経験したので，文献的考察を加えて報告する。

Myopericytoma is a newly-described benign soft tissue neoplasm showing perivascular myoid differentiation. This tumor usually arises from the limbs of the elderly,but its occurrence in the head and neck is extremely rare. An 81-year-old woman presented with a gradually increasing painless mass of the floor of the mouth. Physical examination,CT and MRI revealed a 30×25-mm well-defined ovoid tumor just beneath the mucosa of the floor of her mouth. The tumor was transorally excised with preservation of the Wharton duct and the lingual nerve. The surgical specimen was histopathologically and immunohistochemically diagnosed as myopericytoma. The postoperative clinical course was uneventful,and the patient was discharged 14 days after surgery. The clinical and pathological characteristics of myopericytoma were bibliographically reviewed