Abstract
Costal osteoid osteoma is a rare benign tumor that can be diagnostically challenging due to its atypical location and nonspecific symptoms. We report the case of a 49-year-old male presenting with chronic right-sided chest wall pain for three years. Initial radiographs were normal, but CT imaging and bone scintigraphy later revealed a focal lesion on the ninth right rib. Surgical resection was performed, confirming the diagnosis histologically. The patient subsequently developed persistent moderate intercostal neuropathic pain. This report illustrates the diagnostic pitfalls of rib-localized osteoid osteoma, particularly when initial imaging is inconclusive, and emphasizes the importance of considering this rare entity in patients with unexplained chronic thoracic pain.