A giant osteoma is a rare, benign bone tumor composed of mature bone that most often arises in the skull and facial bones, particularly the frontal or ethmoid sinuses and the mandible. While small osteomas are typically slow-growing and asymptomatic, the term “giant” is applied when they exceed about 3 cm in size or cause significant symptoms. Depending on their location, giant osteomas may lead to visible swelling, facial asymmetry, sinus obstruction with headaches or infections, difficulty che