Histological aspects of rhinosinusal polyps

Rev Bras Otorrinolaringol 2008;74(2):207-12. original article Histological Aspects of Rhinosinusal Polyps Luciano Gustavo Ferreira Couto 1, Atílio Maximino Fernades 2, Daniel Ferracioli Brandão 3, Dalisio de Santi Neto 4, Fabiana Cardoso Pereira Valera 5, Wilma T Anselmo-Lima 6 Keywords: biopsy, histological classification, light microscopy, nasal polyp. Summary C ontemporary cohort cross-sectional study. Introduction: Despite its importance for an accurate diagnosis, histology differences among nasal polyps and its clinical implications are rarely reported in the literature. The existing papers classify polyp samples without concern for prior treatments, which could influence the results attained. Aims: carry out a morphological study, through light microscopy, of nasal polyps’ structural alterations in the absence of any type of prior treatment and histologically classify it in relation to studies published in the literature. Materials and Methods: We studied 89 patients with nasosinusal polyps without prior treatment. Polyp samples were collected by outpatient biopsy and analyzed through light microscopy after dyeing with hematoxylin-eosin. Results: Samples were classified in the following way: Edematous or eosinophilic polyp 65 cases (73%); fibro-inflammatory polyp: 16 cases (18%); Polyp with Sero-mucinose gland hyperplasia: 06 cases (6.7%) and polyp with stroma atypia: 2 cases (2.3%). Discussion: eosinophilic pattern prevailed in the patients with nasosinusal polyps of the population studied. This pattern is similar to the ones found in the major studies, which, however, do not mention prior treatment. Conclusion: after analyzing the polyps’ histological characteristics, we noticed that the untreated polyps present a predominantly eosinophilic pattern. 1 Otorhinolaryngologist. Graduate student (master’s degree). Doctor in otorhinolaryngology, Ribeirão Preto Medical School, São Paulo University. Regular physician of the Otorhinolaryngology Unit, São Jose do Rio Preto Medical School, FAMERP. 3 Master in pathology, Ribeirão Preto Medical School, São Paulo University. Assistant physician in the Pathology Department of the Clinical Hospital, Ribeirão Preto Medical School, Sao Paulo University. 4 Master in pathology. Professor in the Pathology Department, São Jose do Rio Preto Medical School, FAMERP. 5 Doctor in otorhinolaryngology, Ribeirão Preto Medical School, São Paulo University. Regular physician of the Ophthalmology, Otorhinolaryngology and Head & Neck Surgery Department, Ribeirão Preto Medical School, São Paulo University. 6 Livre docente habilitation professor of the Ophthalmology, Otorhinolaryngology and Head & Neck Surgery Department, Ribeirão Preto Medical School, São Paulo University. Associate professor of the Ophthalmology, Otorhinolaryngology and Head & Neck Surgery Department, Ribeirão Preto Medical School, São Paulo University. Ribeirão Preto Medical School, São Paulo University. Address for correspondence: Profa. Dra. Wilma T. Anselmo-Lima - Departamento de Oftalmologia e Otorrinolaringologia e Cirurgia de Cabeça e Pescoco do Hospital das Clinicas da Ribeirão Preto Medical School, São Paulo University - Av. Bandeirantes 3900 Ribeirão Preto SP 14049-900. Tel. (0xx16) 3602-2862 - Fax (0xx16) 3602-2860. Paper submitted to the ABORL-CCF SGP (Management Publications System) on December 29th, 2006 and accepted for publication on September 1st, 2007. cod. 3572. 2 Brazilian Journal of Otorhinolaryngology 74 (2) March/April 2008 http://www.rborl.org.br / e-mail: 207 INTRODUCTION After explanations and consent, patients underwent nasal polyp biopsies in an outpatient setting. Two or three Representative samples of lesions per patient were taken with Takahashi forceps. These samples were fixated in a formalin solution (10% formaldehyde), included in paraffin; 5μm sections were made, which were hematoxylin/eosin stained. Histological sections were made preferentially along the longitudinal axis of polyps for mounting the slides. Polyp samples were exhaustively investigated using optic microscopy to characterize their morphological structure. This investigation was done at the pathology unit of our institution. Histological findings were grouped for classifying the polyps according to the following criteria: 1. Edematous or eosinophilic polyps: features stromal edema containing numerous eosinophils and mast cells, goblet cell hyperplasia in the respiratory epithelium and basal membrane thickening separating the epithelium from the edematous stroma. 2. Fibroinflammatory polyps: features a marked inflammatory infiltrate containing mostly lymphocytes. Other features include lack of stromal edema and goblet cell hyperplasia. 3. Polyps with seromucinous gland hyperplasia: features numerous seromucinous glands and ductal structures in an edematous stroma. 4. Polyps with stromal atypia: its characteristic feature is the presence of bizarre and atypical stromal cells. Cells may be irregular and hyperchromatic. The Research Ethics Committee analyzed and approved this study. The process number was 8484/2005. Nasal polyposis is a chronic non-neoplastic inflammatory disease that is commonly encountered in clinical otorhinolaryngology.1 Its estimated incidence in the general population is 0.5 to 4%.2 Clinical manifestations include nasal obstruction, anterior and posterior rhinorrhea, anosmia and/or hyposmia, headaches and general malaise.3,4 Most of the polyps originate in the nasal mucosa of the middle meatus, although other ethmoidal sites may be involved.5 The etiology and pathogenesis of nasal polyposis has been studied since ancient times;6 however, in spite of the current understanding of this condition, particularly the role of inflammation, the mechanisms that cause nasal polyps remain unknown.7 Tos and Morgensen8 described rhinosinusal polyps histologically as having an edematous, predominantly eosinophil-infiltrated myxoid stroma covered by respiratory epithelium, which frequently presents hyperplasia or squamous metaplasia. In the literature, however, there have been few studies on the histological differences among nasal polyps and possible clinical implications of such differences, which may be important for a precise diagnosis.9 The few existing papers on this topic have classified polyp samples collected in endoscopic surgery, but with little concern about the influence of previous topical or systemic therapy on the histology of these nasal polyps.10-12 Davidsson and Hellquist10 assessed 95 patients and found that an eosinophilic pattern was present in 83.6% of cases. In a study using optic and electronic microscopy we undertook in 2001,12 however, we found no eosinophilic polyps in 17 nasal polyps collected during surgery. On the other hand, the fibroinflammatory pattern that was found in most cases may have been due to two reasons: a difference in the predominant histological type, as occurs in the Asian population,13 or the influence of t (...truncated)