The mucocele of the paranasal sinuses is a kind of retention saccular cyst of any one paranasal sinus, which is formed as a result of obliteration of the nasal excretory duct and the accumulation of mucous and hyaline secretion inside the sinus, as well as elements of desquamation of the epithelium [1, 3, 6]. Most often, the mucocele of the paranasal sinuses is localized in the frontal sinus (80%), then in the ethmoid labyrinth (15%) or on the border between them, which often leads to the penetration of the “cyst” into the orbit,calling exophthalmos, a fact that explains its frequent detection by ophthalmologists. Very rarely, the mucocele is localized in the sphenoid and maxillary sinuses (5%).