[Differential diagnosis of tumors of the soft tissue of the forearm: an atypical palmaris longus muscle].

Bellies of the palmaris longus which are situated in an atypical position can appear as tumors of soft tissues on the flexor side of the forearm. Besides a central position a distal bicipital and a doubled variant can be observed. We report the case of a 22 years old female patient, with a "tumor" on the flexor side of the forearm of plum-size. Previous surgery had been interrupted when musculature appeared. During the revision we found a belly of the palmaris longus in a central position, situated proximal to the flexor retinaculum. The belly of musculature was 5 cm long and 2 cm wide. After extirpation of the tendinous and muscular parts the patient was free of symptoms.