[Mucocele of sphenoid sinus: presentation of 3 cases]

Sphenoidal mucoceles are equally distributed between males and females occur rarely and have an incidence of 1%. Their low incidence is certainly to be ascribed to their deep position with respect to the superior respiratory tract as well as to the characteristics of the mucosa coating of the sinus (where the scarce muciparous component does not cause drainage problems). During endocranial manifestation, it is important to make a differential diagnosis between tumors at the base of the skull and adenomas of the hypophysis. The most feasible etiopathogenetic hypotheses are insufficient drainage of the sinus, cystic degeneration of the ghiandolar epithelium, presence of embryonal remnants and previous surgery. The Authors report three cases of mucoceles located in the sphenoid, two of which with destruction of the sellar floor and upward invasion, one with posterior invasion and involvement of the clivus. Sphenoidal mucoceles generally tend to spread more frequently in an anterior-inferior fashion with invasion of the etmoid, the nasal fossae and the rhinopharynx. In some cases we observe upward invasion with destruction of the sellar floor, as in the first two patients. There may by an invasion in the orbital cavity when spreading occurs sideways. More rarely, the intermediate cranial fossa is invaded through the lateral wall and the posterior cranial fossa through the posterior wall. Therefore, it is evident that an early diagnosis is always desirable because it may spare the patient the neurological manifestations resulting from the evolution of the disease. The treatment for a sphenoidal mucocele is surgical. The Authors report a synthesis of the surgical techniques most frequently used by otorhinolaryngologist and neurosurgeons, and present a critical analysis of the cases presented.