Subacromial pigmented villonodular synovitis: case report and review.

Pigmented villonodular synovitis (PVNS) is a non-neoplastic proliferative process that involves synovial tissue in the joints, tendon sheaths and bursae. It usually occurs in young adults, aged 20-50 years, is characteristically monoarticular and of slow progression. Clinical symptoms are nonspecific, and joint stiffness and pain are common in long-term cases. Shoulder PVNS is known to be extremely rare, especially when affecting the subacromial bursal region without joint involvement. Magnetic resonance is the imaging modality of choice in PVNS and is useful for diagnosis, surgical planning and monitoring. Complete surgical synovectomy remains the treatment of choice, and all pathological synovial tissue should be removed. Patients who are not properly treated can progress to joint destruction. We describe a case of PVNS in the subacromial bursa of a 15-year-old patient, with exuberant symptoms and 2 years of evolution, treated with extensive synovectomy and good clinical results in the 1-year follow-up.