Unusual case of frontal mucocele presenting with forehead ulcer.

Paranasal mucoceles are benign slow-growing paranasal sinus lesions, which usually develop following the obstruction of the sinus ostiu. They most frequently occur in the frontal sinus. Frontal mucoceles are expansive lesions usually causing visual clinical signs and symptoms such as diminution of vision, visual field defects, diplopia, orbital swelling, retroorbital pain, displacement of eye globe, ptosis, and proptosis. When the frontal mucocele extends intracranially, it can manifest with meningitis, meningoencephalitis, intracranial abscess, seizures, or cerebrospinal fluid fistula. Very rarely it can cause forehead swelling. We report an 80-year-old woman presenting with a forehead skin ulcer and painless subcutaneous forehead induration. Histopathologic examination revealed mucin deposition and inflammation. Computerized tomography (CT) and magnetic resonance imaging (MRI) scans showed a mass originating from the frontal sinus with frontal bony defect and frontocutaneous fistula. Surgical excision of the mass confirmed the mucocele diagnosis. In this article, we present a case of frontocutaneous fistula and skin ulcer, which is an unexpected complication of frontal mucocele. We propose that in the case of a localized non-healing ulcerated forehead skin lesions, mucocele should be considered in the differential diagnosis.