[Decompensation of a supinator syndrome in submuscular lipoma. A rare differential diagnosis of elbow pain].

Important differential diagnoses to epicondylitis humeri radialis are the nerve compression syndromes of the elbow. After a long period of conservative treatment, paresis of the motor branch of nervus radialis in this case led to the diagnosis and surgical treatment showing an unknown submuscular lipoma as the cause of a supinator syndrome with paresis of the finger extensors. In cases of therapy-resistant pain of the elbow, especially resistant to the conservative therapy of an epicondylitis humeri radialis, a nontraumatic supinator syndrome should be considered as a differential diagnosis. A tumor as the cause of a compression syndrome of the motor branch of the nervus radialis is very rare.