Occipital Condyle Osteoid Osteoma with Severe Occipital Pain that Disappeared after Surgical Resection

Osteoid osteoma is a benign bone tumor characterized by local pain that typically increases at night. The tumor commonly occurs in the long bones of the lower extremities, and in rare instances in cranial bones. Here we report the case of a 25-year-old man diagnosed with an osteoid osteoma of the right occipital condyle. The patient suffered from severe occipital pain in the 3 years leading up to surgery, and the pain disappeared after surgical resection of the tumor. Due caution must be taken to avoid vertebral artery injury in the surgical approach in this region. An intraoperative navigation guidance system and preoperative analysis using three-dimensional reconstructed computed tomography (CT) images improved the accuracy and safety of the resection. The typical pain in osteoid osteoma is presumed to be associated with prostaglandin E2 secretion. Plasma prostaglandin E2 of this patient was elevated preoperatively and normalized after the operation. This is the first report describing an elevation of plasma prostaglandin E2 before surgical resection followed by a normalization of serum prostaglandin E2 after surgical resection.