Tender lesion fourth digit Examination of the right hand reveals a soft tissue mass along the volar lateral aspect of the fourth proximal phalanx. The lesion measures approximately 11 x 23 mm and extends from just distal to the proximal inner phalangeal joint to just distal to the distal interphalangeal joint. The lesion is homogeneously of increased signal on the T2-weighted images and isointense with muscle on the T1-weighted images. With intra-articular gadolinium there is peripheral enhancement with a central area of nonenhancement. The walls of this lesion are somewhat thickened.
Most likely a synovial cyst of the fourth digit. Somewhat unusual in that it has a thickened wall. The diagnosis could be confirmed with aspiration. 