Necrotizing squamous metaplasia in herpetic tracheitis following prolonged intubation: a lesion similar to necrotizing sialometaplasia.

In the last year we have encountered three cases of clinically inapparent herpes simplex virus (HSV) tracheitis in biopsies from patients undergoing tracheostomy following prolonged intubation. The diagnosis was based on finding characteristic inclusion-bodies on haematoxylin and eosin stained sections and was confirmed by immunohistochemical staining of infected cells with antibodies to HSV. A prominent mononuclear infiltrate, originally described in HSV oesophagitis, was recognized in two cases. Diffuse squamous metaplasia of both surface and glandular epithelium adjacent to necrotic ulcerated areas was evident in all three cases. Where extensive, the necrotizing squamous metaplasia of the glandular/ductal component was similar to necrotizing sialometaplasia of salivary glands, and likewise simulated squamous or mucoepidermoid carcinoma.