Fibroma of tendon sheath is an uncommon benign soft tissue tumor with a predilection for the hand. A unique case involving the scapholunate and radiocarpal joints with bone erosion is reported. The patient presented with a transilluminating mass over the volar radial wrist associated with neuropathy in the superficial radial nerve distribution. Magnetic resonance imaging demonstrated a heterogeneous and lobulated mass with nonspecific signal characteristics closely associated with the scapholunate interval and the volar wrist soft tissues. Histologically it represented a fibroma of tendon sheath. The tumor is discussed and the relevant literature is reviewed.