[Giant mucocele of the paranasal sinuses with extension to the contralateral posterior cranial fossa and reversible retrocochlear deafness].

Report on a huge mucocele of the right maxillary sinus extending into the ethmoid and sphenoid sinuses, and protruding into the contralateral left posterior cranial fossa. The patient, a 45-year old male, had no history of paranasal sinus energy, nasal or paranasal symptoms. He went to his physician because of a slowly developing deafness in his left ear and because of episodes of loss of consciousness when blowing his nose. A reversible episode of vertigo and reversible paresis of the left abducent nerve 17 years previously, were later assumed to have been the first symptoms of endocranial extension of the mucocele. The diagnosis of a mucocele was made by MRI. MRI in T2 weighted spin-echo sequences is the best imaging technique for diagnosing a mucocele. The mucocele was treated primarily with endonasal surgery of the paranasal sinuses, using telescopes and an operating microscope. After opening the right maxillary sinus via the middle meatus liquid contents of the mucocele poured into the nasal cavity. The sack of the mucocele was removed partially. Three months later the patient was reoperated with a combined transfacial and endonasal approach, because of progression from partial hearing loss to total deafness. Postoperatively hearing improved nearly completely and compression of the pons and the posterior fossa had disappeared on MRI. It is concluded that in mucoceles no longer the extirpation of the sack, but endonasal marsupialization, using the operating microscope and telescopes, is the therapy of choice.