Squamous metaplasia of the subglottic space and its relation to smoking.

A macroscopic staining method was used to assess the incidence and extent of squamous metaplasia of the subglottic portion of the larynx. A total of 226 postmortem specimens were studied, 105 from nonsmokers and 121 from smokers. More than half of the specimens stained showed some metaplasia, but the incidence and extent of metaplasia was greater in smokers than in nonsmokers, and women were more affected than men. The incidence of metaplasia was greater in pipe and cigar smokers than in nonsmokers, but previous smokers did not differ from nonsmokers.