Morphological and clinical characteristics of antrochoanal polyps: comparison with chronic inflammation-associated polyps of the maxillary sinus

Objectives: to compare morphological and clinical features of antrochoanal polyps and chronic inflammation-associated polyps of the maxillary sinus. S tudy design: histological and scanning electron microscopic examination of ten antrochoanal polyps and ten chronic inflammation-associated polyps of t he maxillary sinus; comparison of clinical data in both groups of patients. Methods: following surgical removal, the polyps were halved, the halves be ing processed for routine light microscopy (formalin fixation, paraffin emb edding, HE staining) and scanninng electron microscopy: (formaldehyde/gluta raldehyde fixation, critical point drying, gold coating), respectively. Cli nical data were retrospectively reviewed, tabulated and compared. Results: the antrochoanal polyps differed from chronic inflammation-associated polyp s of the maxillary sinus only in a few minor features; slightly longer dura tion of the process, lower incidence of maxillary ostial obstruction, highe r incidence of frequent headaches, persistent nasal obstruction, presence o f cysts in the polyp stroma, thickened basement membrane, lower incidence o f squamous cell metaplasia. and higher proportion of migratory cells in nas al smears. In two cases, allergy was diagnosed but it seemed not to influen ce the polyps: which did nut show morphological features typical of allergy -associated (eosinophilic) polyps. Conclusions: In spite of minor differenc es, antrochoanal polyps can be: regarded as chronic inflammation-associated polyps with cystic origin and peculiar localization. (C) 2001 Elsevier Sci ence Ireland Ltd. All rights reserved.