성인에 발생한 근섬유종증형 혈관주위근종

초록

Myofibromatosis is a rare bu well recognized entity which considered to arise exclusively in neonates and infacts and is extremely rare in adults. Recently, adult myofibromatosis, glomangiopericytoma and myopericytoma were categorized as a perivascular myoma. We report a case of myofibromatosis type perivascular myoma arising in an adult patient. A 47-year-old man was admitted to out hospital because of palpable masswhich was slowly growing for 6 years in the right knee. He had medical history of three times of operation due to colon cancer, stomach cancer and testicular seminoma several years ago and underwent radiotherapy. The tumor was located in the subcutaneous tissue and measured 1.x1.0cm. It was well circumscribed but not encapsulated. Histologically, it showed a biphasic pattern that consisted of fascicles of spindle cells with abundant eosinophilic cytoplasms that resembled smooth muscle surrounding thin and thick walled bessels, in addition to a population of more cullular areas of primitive small, ovoid to spindled cells with scant cytoplasm, focally associated with hemangiopericytoma-like vascular pattern. The arrangement of the two components was a pattern of reverse zonation. The tumor cells were diffusely immunoreactive for smooth muscle actic and vimentin, focally positive for desmin n the spindle cell myoid area, but not reactive for S-100 protein, CD34 and CD68. This tumo showed characteristic histologicfeature which enable to be distinguished from other fibrous lesions and from benign or malignant smooth muscle tumors.