A 51-year-old woman with myxoma in the vastus medialis muscle is reported. She became aware of swelling in the right thigh in June, 1984 and admitted to the hospital two weeks later. On admission, a tumor was palpable in the right thigh and seemed to be in the deep portion of soft part tissue. We diagnosed this tumor to be a benign soft part tumor and carried out the resection of the tumor. The tumor was found in the vastus medialis muscle and separated from the tissue around the tumor completely. Pathological examination revealed intramuscular myxoma and no evidence of malignancy. At four months postoperatively the patient has no complaint.
