Osteoid osteoma of the great toe.

Osteoid osteoma is a relatively common osteoblastic lesion of benign skeletal neoplasms and occurs most commonly in the cortex of long bones, especially the femur and the tibia. Radiological characteristics are a nidus that appears as a small, relatively radiolucent zone within an area of extensive reactive sclerosis. Clinically, the lesion presents with increasing pain, is worse at night, and is relived by nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoid osteomas involving the phalanges of the toes are uncommon, and its accurate preoperative diagnosis is difficult due to the unique clinical and radiological features. The features in the phalanx of the toe are soft tissue swelling and a nidus frequently located in the cancellous without osteosclerosis. This article presents a case of a 22-year-old man with osteoid osteoma in his distal phalanx of the hallux. A needle biopsy of his great toe revealed a small number of bacteria, so he was initially treated for osteomyelitis but with unsatisfactory results. The particular characteristics of clinical and imaging findings supported a diagnosis of osteoid osteoma in the distal phalanx of the hallux. After surgical removal of the tumor, his symptoms resolved. The pathological examination confirmed the suspected diagnosis. In a patient with chronic foot pain that changes to become nocturnal and disappears with NSAID administration, it is important to include osteoid osteoma as a differential diagnosis. A detailed assessment of both clinical and radiological features can lead to the correct diagnosis, which must be confirmed with histopathological examination to ensure adequate excision.