A 17-year-old boy with pyrexia, headache, and frequent drop attacks reported an acute onset of periorbital pain and swelling 1 month previously. Coronal computed tomography (CT) identified an ethmoid sinusitis, which was treated with functional endoscopic sinus surgery and intravenous gentamicin, prostaphylline, and metronidazone. Because of persistent symptoms, the patient returned 1 month later. The CT identified accumulation of debris in both frontal sinuses and a multilobulated lesion over the right frontal lobe. Bicoronal craniotomy was performed, and a mass located in the right frontal lobe was excised; the mass comprised chronic inflammatory tissues without evidence of malignancy. A postoperative brain CT confirmed the absence of a residual mass, and no recurrence or neurologic deficits were noted during the 3-month follow-up period. Intracranial complications cannot be prevented entirely even with the judicious use of antibiotics. Early application of the appropriate imaging modality and institution of aggressive therapy in any patient, not just pediatric patients, to prevent potential long-term disabilities and death are essential.