Pigmented villonodular synovitis of the flexor hallucis longus tendon: a case report and review of the literature

Abstract

Pigmented villonodular synovitis is a rare, locally aggressive disease affecting the synovial joints, bursas and tissues that involve tendons. Giant cell tumors of the tendon sheath are considered an extra-articular form of pigmented villonodular synovitis. This distinctive tumor is most often found in the sheath of hand tendons and is less common in feet. Because few cases have been reported in the literature, this report describes the disease, mainly in relation to the flexor hallucis longus tendon.