Study of Pattern and Significance of Infiltration of Eosinophil and Mast Cells in Nasal Polyp

Introduction: Nasal polyps are hypertrophied, oedematous mucosa of the nasal cavity and paranasal sinuses,commonly classified as bilateral nasal polyposis (B/L polyposis) or antrochoanal polyps (ACP). Inflammatorycells such as eosinophils and mast cells play a key role in their pathogenesis.Aims: To evaluate eosinophil and mast cell infiltration in nasal polyps, compare infiltration between B/Lpolyposis and ACP, and correlate tissue eosinophilia with systemic eosinophil levels.Materials and Methods: This cross-sectional observational study was conducted in the Department ofPathology at Nil Ratan Sarkar Medical College and Hospital, Kolkata and Department of ENT at IPGMER &SSKM Hospital, between January 2024 and June 2025. The study included 50 cases of nasal polyps—bothbilateral nasal polyposis and antrochoanal polyps—encompassing patients of all ages and both sexes.Participants were enrolled after obtaining written informed consent and Institutional Ethics Committee approval,resulting in a final sample size of 50 cases.Results: Of 50 cases, 36 (72%) had B/L polyposis and 14 (28%) had ACP. Median eosinophil count/HPF was40 in B/L polyposis versus 11 in ACP (p<0.05). Mast cells in epithelium: median 2.5/10 HPF in B/L polyposis,0 in ACP; in stroma: 23 versus 7.5 (both p<0.05). Tissue eosinophilia (>5/HPF) was present in all cases, whileonly 5 patients had blood eosinophilia. Tissue and blood eosinophil counts showed no significant correlation(r=0.224, p>0.05).Conclusion: Local eosinophil and mast cell infiltration is significantly higher in B/L polyposis compared toACP, suggesting their key role in pathogenesis. Anti-inflammatory therapy should be considered the mainstay inmanaging bilateral nasal polyposis.