Abstract
This review covers the histopathology and pathogenesis of non-infectious inflammatory diseases of the sinonasal tract, in particular, sarcoidosis, granulomatous vasculitides Wegener, Churg-Strauss), relapsing polychondritis, eosinophilic angiocentric fibrosis, chronic rhinosinusitis and nasal perforations. Molecular associations and mechanisms are emphasised to assist pathologists to put their observations into the context of clinical, genetic and environmental influences on patients' diseases.