A 58-year-old woman visited our hospital’s emergency department because of a severe and increasing pain over the right occipital region, irradiating over the right frontal area. The pain started during the descent of a jet airplane on a holiday trip. There were no visual or hearing deficits, head trauma, or epistaxis, and she experienced no difficulty clearing her ears during the flight. Only a minor respiratory tract infection was noted two weeks before this episode, and she had no history of sinus problems. The pain was nothing like previous migraine headaches she had experienced. A noncontrast CT scan was performed which showed no apparent abnormal findings, except for a soft tissue density in the right frontal sinus, initially interpreted as an inflammatory mucosal swelling. Because of the atypical and persistent headache, MRI imaging was performed to exclude underlying pathology. No intracranial mass, hemosiderin deposits, or arteriovenous malformation were observed. A polypoid mass was noted in the right frontal sinus, hyperintense on T1and T2-weighted images, without enhancement after contrast administration (Figures A and B). Considering the clinical history and MRI appearance, the diagnosis of submucosal hematoma secondary to barotrauma was made. Conservative treatment with oral decongestants and analgesics resulted in satisfactory symptom relief.