Giant-cell reparative granuloma of the hand and foot bones.
 Giant-cell reparative granuloma (GCRG) is an uncommon benign reactive intraosseous lesion.
 It occurs in the skull, jaw, hand, foot, and facial bones and rarely in other skeletal sites.
 It is a solitary, lytic, expanded lesion and infrequently may extend into the surrounding soft tissue.
 Histologically, it is composed of fibrous stroma with spindle-shaped fibroblasts, multinucleated giant cells, and inflammatory mononuclear cells.
 Areas of hemorrhage are uniformly present.
 It may be difficult to distinguish this entity from an aneurysmal bone cyst, giant-cell tumor, or brown tumor of hyperparathyroidism because of roentgenographic and histologic similarities.
 Accurate diagnosis is essential for appropriate treatment; serum calcium, phosphorus, and parathyroid hormone levels should be measured.
 Curettage and bone graft are effective treatments for both primary lesions and recurrences.
 Second recurrences are rare.
