METHODS: We performed a comprehensive review of the literature regarding definition, etiology, epidemiology, natural course, and best treatment of MMC.
RESULTS: Among the 988 papers found in the literature search, 33 studies were selected to be relevant. Among those studies, there are only a few prospective controlled studies. Their prevalence rates range broadly from 3.6% to 35.6% according to different diagnostic methods as well as different indications for imaging. Recent prospective studies showed no correlation of MMC with sinonasal complaints or Lund-Mackay computed tomography (CT) score. The natural course is characterized by a decrease in size of MMC in 30% of the cases, an unchanged status in 50% to 60%, and an increase in 8% to 20% of the cases.
CONCLUSIONS: MMC are harmless, mostly asymptomatic lesions that usually do not need surgical treatment. If surgery is indicated, endonasal endoscopic techniques should be the gold-standard approach.