Intraosseous epidermoid cyst of the distal phalanx reconstructed with synthetic bone graft.

Intraosseous epidermoid cysts are exceedingly rare. Known as pseudotumors, not true neoplasms, intraosseous epidermoid cysts usually involve the phalanges, the skull, and the toes. Intraosseous epidermoid cysts typically present as destructive osteolytic lesions on X-ray, mimicking malignant bone tumors. Here, we present two cases of an intraosseous epidermoid cyst in the distal phalanx treated with curettage and synthetic bone graft, followed by a review of the relevant literature. In both cases, the patient presented with a painful enlargement of the fingertip following a minor trauma. Magnetic resonance imaging demonstrated lesions involving the distal phalanx that had a low signal on T1-weighted imaging (WI) and a high intensity on T2-WI. In both cases, the lesions were not enhanced by gadolinium. Good remodeling and functional recoveries were obtained. For physically active patients with substantial bone defects, synthetic bone graft may be recommended.