Intramuscular myxoma

Eighteen cases of intramuscular myxoma are described. All except 3 were collected during the last 12 years at the Department of Pathology, Sahlgren Hospital, Göteborg, which obtains biopsy material from a part of Sweden inhabited by some one million people. The tumor showed a preponderance in women and was most frequently situated in the thigh. Histochemical studies with the Scott technique for glucoseaminoglycans, i.e. staining with Alcian blue with the addition of increasing concentrations of MgCl2, indicated the presence of hyaluronic acid, as did also staining with Alcian blue or toluidine blue at different pHs, and pretreatment of histologic sections with bovine hyaluronidase. Histologic study of all tumors, preoperative angiography in 6 patients, and microangiographic study of 2 tumors revealed that the intramuscular myxoma is a poorly vascularized tumor. In contrast, high vascularity was observed in a microangiographically studied case of myxoid liposarcoma, which is an important differential diagnosis of intramuscular myxoma. All patients were treated by muscle resection or myectomy. Recurrence or metastasis was not seen in any of the patients during an observation time of 1 to 24 years.