A Case of a Giant Cell Tumor of the Tendon Sheath of the Middle Phalanx of the Fourth Toe.

Giant cell tumors of the tendon sheath (GCT-TS) are one of the most common tumors of the hand, along with ganglions. However, occurrence in the toes is far less common. Here we present a rare case of GCT-TS at the middle phalanx level of the flexor digitorum longus tendon sheath. Magnetic resonance imaging showed low intensity both on T1 and T2 weighted images. To the best of our knowledge, our case is the first report of a GCT-TS arising at the middle phalanx level of the flexor digitorum longus tendon sheath of the fourth toe. Although GCT-TS are rare in the toe, they must be included in the differential diagnoses of soft tissue tumors arising in the toes.