Neuromuscular hamartoma.

A rare case of neuromuscular hamartoma, a benign tumor composed of well-differentiated skeletal muscle and nerve fibers, is described and compared with four previously reported cases. The tumor arose in the major peripheral nerves. Three of the five tumors were congenital tumors. A biopsy is essential in establishing the diagnosis. However, the tumor may be left alone if it cannot be separated from the nerve with ease, since spontaneous regression has been documented.