Frontal Sinolith.

Sinolith in the paranasal sinus is still a rare entity. A sinolith in the frontal sinus is extremely rare, and only 2 patients have been reported in the English literature. Herein, the authors present an additional patient of frontal sinolith in a 78-year-old woman. The patient was preoperatively diagnosed with fungus ball of the frontal sinus, based on radio-opaque densities on computed tomography. Endoscopic surgery was performed and surgical biopsy was interpreted as sinolith. Clinical manifestations of frontal sinolith, including imaging study findings, are discussed with a review of the literature pertaining to this condition. Despite its rarity, frontal sinolith should be considered in the differential diagnosis of radio-densities in the frontal sinus.