Unusually delayed manifestation of a hallux osteoid osteoma: A case report

INTRODUCTION: Osteoid osteomas are benign osteoblastic bone tumors mostly seen in patients in the second or third decade of life, and they most frequently involve the femur and tibia. Hallux osteoid osteoma is an extremely rare occurrence with only 14 reported cases to date. PRESENTATION OF CASE: A 46-year-old woman with a right hallux pain for the last 18 months was admitted. Her foot radiographs showed a small sclerotic focus on the distal phalanx and degenerative changes in the interphalangeal joint of the hallux. The complaints of the patient were attributed to osteoarthritis involving the interphalangeal joint and non-steroidal anti-inflammatory drugs were administered; however, the patient’s condition did not improve, and hallux osteoid osteoma could not be correctly diagnosed until a CT scan was performed. DISCUSSION: We present a case of hallux osteoid osteoma in which the diagnosis was delayed greatly due to the unusuality of the lesion location, the advanced age of the patient, and the uncertainty of the clinical and radiographic appearance. CONCLUSION: Although rare, osteoid osteoma may occur in the hallux. Even if the patient age, pain pattern, and radiographic findings do not exactly meet the classical definitions for osteoid osteoma, this tumor should always be included in the differential diagnosis list in patients presenting with foot pain.