Eosinophil–Mast Cell Inflammation in Middle Ear Effusion Associated With Chronic Rhinosinusitis With Nasal Polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is predominantly associated with type 2 inflammation, although the inflammatory profile may involve both eosinophils and mast cells. Middle ear disease in CRSwNP is usually attributed to Eustachian tube dysfunction, but inflammatory involvement of the middle ear may also occur. We report the cytological evaluation of middle ear effusion from a patient with CRSwNP. May-Grünwald-Giemsa staining revealed eosinophils, mast cells, and extracellular granules consistent with degranulation. The simultaneous presence of these cellular components suggests an active type 2 inflammatory microenvironment rather than a purely mechanical or obstructive effusion. This observation supports the hypothesis that, in selected patients with CRSwNP, middle ear involvement may represent an extension of the sinonasal inflammatory process. Cytological assessment may therefore provide additional information for inflammatory phenotyping of middle ear disease associated with CRSwNP.