History of index finger mass. A marker was placed along the volar and ulnar aspect of the index finger at the level of the middle phalanx. Deep to the marker is a lobular mass replacing the subcutaneous fat of the index finger centered within the volar and ulnar soft tissues at the level of the DIP joint. The mass extends from the skin surface to the underlying phalanges. It also contacts the volar surface of the flexor tendon apparatus. Smaller lobular components of the mass extend along the radial aspect of the base of the distal phalanx as well as dorsal to the head of the middle phalanx deep to the extensor tendon apparatus such that there is essentially circumferential involvement. There is no clear bone or joint involvement, however. Due to the circumferential involvement of the mass, it is somewhat difficult to measure. However, it measures approximately just under 3 cm in the longitudinal dimension extending from the level of the mid diaphysis of the middle phalanx to the midportion of the distal phalanx. Overall, the mass measures approximately 2 cm in the greatest transverse dimension (medial-lateral). The mass is isointense to skeletal muscle on T1-weighted images and is heterogenous but predominantly of low signal on T2-weighted images. The mass enhances diffusely following contrast administration.
1.Minor contrast reaction as described above. Reaction documented in EPIC, and patient provided with discharge instructions.2.Soft tissue mass of index finger which circumferentially surrounds the phalanges with signal characteristics suggestive of giant cell tumor of tendon sheath.