Simultaneous pigmented villonodular synovitis and synovial chondromatosis of the hip: case report.

This report presents a case of a 37-year-old female with a history of hip pain. Magnetic resonance arthrography revealed loose bodies within the joint and synovial hypertrophy indicative of synovial chondromatosis (SC). Hip arthroscopy revealed free chondral bodies and focal villonodular synovial proliferation. The focal synovial proliferation was excised, a total synovectomy performed, and all cartilaginous free bodies removed. A post-operative histological examination of the removed nodular mass and synovium yielded evidence of both SC and pigmented villonodular synovitis (PVNS). A 1-year post-operative clinical examination showed marked clinical improvement and no signs of recurrence on MR images. Despite the clinical similarities, PVNS and SC are two distinct conditions that, to our knowledge, have never been reported as simultaneously occurring in a hip joint. The simultaneous presence of both pathologies may suggest a common origin of synovial metaplasia.