Radiological reasoning: Acutely painful swollen finger.

Abstract

The purpose of this article is to review the differential diagnosis of finger masses and their imaging appearances. Giant cell tumor of the tendon sheath is a slowly growing, benign tumor of the synovium that commonly presents as a painless nodular mass in the hand or wrist. Also termed "localized nodular tenosynovitis," these tumors are the most common soft-tissue tumors of the hand. Occasionally, these tumors can present with pain when traumatized, and they should be suspected when a firm, rubbery mass is found at the location of a tendon sheath.