GIANT MUCOCELE OF THE PARANASAL SINUSES, EXTENDING INTO THE CONTRALATERAL POSTERIOR CRANIAL FOSSA AND CAUSING REVERSIBLE SENSORINEURAL HEARING IMPAIRMENT

Report on a huge mucocele of the right maxillary sinus extending into the ethmoid and sphenoid sinuses, and protruding into the contralatera l left posterior cranial fossa. The patient, a 45-year old male, had n o history of paranasal sinus surgery, nasal or paranasal symptoms. He went to his physician because of a slowly developing deafness in his l eft ear and because of episodes of loss of consciousness when blowing his nose. A reversible episode of vertigo and a reversible paresis of the left abducent nerve 17 years previously, were later assumed to hav e been the first symptoms of endocranial extension of the mucocele. Th e diagnosis of a mucocele was made by MRI. MRI in T2 weighted spinecho sequences is the best imaging technique for diagnosing a mucocele. Th e mucocele was treated primarily with endonasal surgery of the paranas al sinuses, using telescopes and an operating microscope. After openin g the right maxillary sinus via the middle meatus liquid contents of t he 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 posteri or fossa had disappeared on MRI. It is concluded that in mucoceles no longer the extirpation of the sack, but endonasal marsupialisation, us ing the operating microscope and telescopes, is the therapy of choice.