長期経過を経て悪性化したと考えられる上顎悪性線維性組織球症（malignant fibrous histiocytoma）の1例

A Case of Malignant Fibrous Histiocytoma of the Maxilla

　はじめに

　悪性線維性組織球症（malignant fibrous his-tiocytoma，以下MFHと略す）は，全身の軟部組織に生じ四肢に好発する腫瘍で頭頸部領域での発生は比較的少ないとされている。今回われわれは，良性腫瘍として手術をうけ，25年間という経過を経て悪性化したと考えられる上顎MFHの1例を経験したので若干の文献的考察を加え報告する。

Malignant fibrous histiocytoma (MFH) has been known as the most common soft tissue sarcoma. However, this tumor is relatively uncommon in the head and neck region. A case of MFH in the right maxillary sinus is reported. Twenty five years ago, the patient was operated on for a benign tumor of the right maxilla. It was considered that infection or inflammation for a long period induced the remain-ing benign tumor to MFH. To date, neither local recurrence nor distant metastasis has been found.