Synovial sarcomas (synoviomas) are rare, malignant tumors which develop in the soft tissues of the extremities and are thought to arise from synovial cells lining joints, tendon sheaths, or bursae, although it must be emphasized that these tumors almost never actually involve synovial membranes. This is the fifth reported case of a synovial sarcoma arising in the anterior abdominal wall. Report of Case The patient, a 46-year-old physician's wife and mother of two children, had been seen frequently at the Hitchcock Clinic over a period of eight years. Her chief difficulties were referrable to uterine leiomyomata and regional enteritis, the latter fairly well controlled by antispasmodics and dietary restrictions. On Jan. 22, 1959, she reported for a scheduled follow-up visit and at that time called attention to a 0.7 cm. subcutaneous, very tender nodule in the left side of the abdominal wall just above the inguinal canal. This had been