Anatomical considerations in the aetiology of fronto-ethmoidal mucoceles.

Aetiological factors in the formation of fronto-ethmoidal mucoceles are examined in 80 patients. The degree and duration of obstruction and the absence of alternative drainage routes are important in the development of this condition but to investigate the mechanism of bone resorption and mucocele expansion, PGE2 levels have been measured in the mucosa from mucoceles and normal frontal sinuses. Significantly greater levels of PGE2 were demonstrated in the mucocele mucosa. Whilst aetiological factors can be defined in 71%, the largest single group has no known cause and it is likely that they represent a vulnerable population in whom there is a degree of intrinsic narrowing and tortuosity of the fronto-nasal duct with total obstruction produced by minor sub-clinical inflammatory changes.