Finger mass Just deep to the flexor tendons of the index finger and slightly distal to the A2 pulley is a well-circumscribed mass measuring approximately 5 x 2 mm. The mass appears intimately associated with the flexor tendon sheath and flattens the underlying flexor tendon. The underlying bone is normal in signal with no evidence of erosive change. This mass demonstrates isointense signal on T1 and is slightly hyperintense on T2 sequences. Following contrast administration, there is suggestion of some enhancement on the coronal postcontrast sequence although there is no significant difference in signal between the axial pre and post images. Probable cyst noted in the head of the third metacarpal.
Well-circumscribed mass appearing intimately associated with the flexor tendon sheath of the index finger. The location and signal characteristics is most suggestive of a giant cell tumor of tendon sheath.