Localized form of congenital generalized fibromatosis. A report of 3 cases with myofibroblasts.

Three cases of the localized form of congenital generalized fibromatosis are described in females under one year. The lesions were in the parotid region, biceps muscle and abdominal wall. The infiltrative or nodular pattern of these tumours with the periphery resembling smooth muscle and the central portion resembling a haemangiopericytoma makes them a distinct histological entity. Ultrastructurally, these tumours are composed of myofibroblasts. The differential diagnosis from other soft tissue tumours in infancy and early childhood is discussed. These tumours are benign and recurrence after complete local excision is rare.