Presentation of osteoid osteoma in the fifth metatarsal: a case report and review of the literature.

BACKGROUND: Osteoid osteoma is a benign bone tumor commonly affecting the lower extremities, typically the femur or tibia. However, its occurrence in the fifth metatarsal bone is rare, and atypical presentations can lead to delayed diagnosis and misinterpretation as other pathologies.

CASE PRESENTATION: We report the case of a 14-year-old Persian male athlete who presented with persistent lateral forefoot pain lasting 2 years, initially attributed to a traumatic injury. The pain was progressively worsening, nocturnal, and unresponsive to nonsteroidal anti-inflammatory drugs, deviating from the classical dramatic relief associated with this tumor. Radiographs initially showed diffuse sclerosis without a visible nidus, further complicating the diagnosis. Computed tomography imaging later identified a well-defined nidus in the neck of the fifth metatarsal, confirming osteoid osteoma. Owing to the atypical symptoms, larger lesion size (> 1.5 cm), and poor response to conservative management, the patient underwent curettage and bone grafting, leading to complete symptom resolution. Histopathology confirmed the diagnosis, and postoperative follow-up showed full recovery with no recurrence at 6 months.

CONCLUSION: This case underscores the importance of considering osteoid osteoma in cases of unexplained, persistent metatarsal pain, even in the absence of classical imaging findings and nonsteroidal anti-inflammatory drug responsiveness. Early recognition with advanced imaging, such as computed tomography, is crucial in preventing misdiagnosis and ensuring timely intervention.