General Medical Information

Mucocele

Barbara A. Zeifer

Mucoceles can occur as obstructive complications of chronic sinus inflammation, polyposis, trauma, surgery, or tumor. The frontal sinus is most commonly involved, followed by the ethmoidal, maxillary, and sphenoidal sinuses. Radiographs show smooth, rounded enlargement of a completely opacified sinus cavity or air cell. This sign indicates the slow nature of the expansile process. The walls are thinned, often barely seen. Maxillary mucoceles often have areas of bony thickening with other areas of thinning due to severe chronic sinus inflammation and the expansile process. At CT, the mucocele contents have low density and do not become enhanced. Intensity characteristics at MRI vary with the protein content of the mucocele and the degree of hydration.