Acute sinusitis: A histopathological and immunohistochemical study

Objective: To provide data on the histopathological and immunohistochemical characteristics of acute sinusitis in humans, Study Design: A nonrandomize d, retrospective, controlled, qualitative and quantitative study. Methods: Inflamed sinus mucosal tissues were removed duping functional endoscopic si nus surgery from 11 patients with acute sinusitis, of whom 6 had complicati ons with extension of inflammation to the orbit (4) or the meninges (2), 3 had recurrent sinusitis, and 2 had acute exacerbation of chronic sinusitis. Normal sinus mucosal tissues were retrieved from four patients with variou s nasal tumors and served as controls, All specimens underwent routine hist ological processing. Representative sections from each region were stained with hematoxylin and eosin, periodic acid-Schiff, and toluidine blue. Immun ohistochemical staining for T and B lymphocytes was also applied. A two-pha se examination was designed: low-magnification microscopic assessment (x40) to yield the typical pathological features and high-magnification assessme nt ( x 400) to count various inflammatory cells. Results: The lamina propri a displayed the most significant changes with edema, extensive infiltration of neutrophils and mononuclear cells, formation of micro-abscesses, thromb ophlebitis, and necrotic foci, whereas the involvement of the epithelial la yer in the inflammatory reaction was relatively modest, Immunohistochemistr y revealed an increase in the population of T and B lymphocytes, The former were diffusely scattered, whereas the latter also formed distinct clusters : around small venules, adjacent to seromucous glands, and under the epithe lium. Conclusions: The inflammatory reaction of the lamina propria exceeded that of the epithelial layer, It is assumed that the clusters of B lymphoc ytes around blood vessels may point to the fact that these cells were recru ited from the blood during acute sinusitis.