47-year-old female with history of trauma, thumb pain and swelling about the flexor tendon. The visualized portion of the flexor pollicis longus tendon is intact as traced from the level of the the first metacarpal to its insertion on the distal phalanx. There is abnormal signal intensity replacing the subcutaneous fat between the volar margin of the flexor pollicis longus and the overlying skin at the crease of the interphalangeal joint. This is of intermediate signal intensity on T1 and T2 weighted sequences and slightly increased signal intensity on fat suppressed T2-weighted images. While this is nonspecific, this may represent focal edema or possibly scar tissue. The volar plate deep to the tendon appears sightly prominent, but we see no evidence to suggest a volar plate injury and this may simply reflect mild osteoarthritis and slight flexion at the interphalangeal joint. There is mild thickening and increased signal intensity of the radial collateral ligament of the interphalangeal joint which we suspect is chronic in etiology. There is also small bony excrescence arising from the metacarpal head which likely reflects old trauma. We see no fluid within the interphalangeal joint, however there is an elongated collection of fluid signal intensity dorsal to the extensor pollicis tendon along the proximal phalanx which likely represents a ganglion cyst which measures approximately 1 cm in the longest dimension.
1.Abnormal signal intensity volar to the flexor pollicis longus tendon volar to the interphalangeal joint. This is nonspecific and may represent edema or scar tissue. The possibility of an A2 pulley injury is also a consideration. The flexor pollicis longus tendon appears normal.2.Degenerative arthritic and possible old posttraumatic changes as above.3.Ganglion cyst dorsal to the proximal phalanx as above.