Giant cell tumor of the tendon sheath with medullary extension: A case report

Giant cell tumor of the tendon sheath with medullary extension in the foot has rarely been reported before. We report a 28-year-old man who had a painless swollen lesion over the proximal phalanx of the second toe of the left foot for several years. Conventional radiographs showed a lobulated lucency in the bone marrow of the proximal phalanx surrounded by a soft-tissue density over the second toe. MRI revealed a 1.2-cm tumor mass at the volar side of the proximal phalanx with medullary extension. Histological findings were compatible with giant cell tumor of the tendon sheath with tumor extension to the marrow spaces.