Case:
An 18-year-old woman presented with shoulder pain that had persisted for a year. The magnetic resonance imaging showed a solitary lesion in the subacromial bursa (SAB). Arthroscopy revealed an ovoid mass connected to the bursal wall with thin synovial tissue that was excised en bloc arthroscopically. Histological and molecular genetic examinations confirmed the diagnosis of fibroma of tendon sheath (FTS). The patient was symptom free for 32 months postoperatively.
Conclusion:
This is the first case in the English literature of an FTS occurring in the SAB. FTS should be included in the differential diagnosis when a nodular lesion is noted in the SAB.