Case report: Biceps tendinitis caused by an osteochondroma in the bicipital groove - A rare cause of shoulder pain in a baseball player

Tendinitis of the long head of the biceps brachii muscle is commonly seen in athletes who do repetitive overhead motions. Common causes of biceps tendinitis include impingement syndrome, subluxation of the biceps tendon, and attrition tendinitis, whereas biceps tendinitis secondary to a bone neoplasm is rare. A case of biceps tendinitis caused by an osteochondroma arising in the left humeral bicipital groove in a 25-year-old male baseball player is reported. The tumor was hook-shaped, originated from the inferomedial portion of the humeral lesser tubercle, and surrounded the biceps tendon. Symptoms of increasing pain and inability to throw resulted from direct irritation of the biceps tendon by the tumor. Total excision of the tumor relieved:the symptoms within 3 weeks. To our knowledge, there have been no reported cases in the English-language literature of biceps tendinitis caused by an osteochondroma.