Pathomorphological features of various etiological forms of aortic aneurysm

<jats:p>Objective. To identify differential diagnostic pathomorphological features of the aortic wall structure in various forms of aortic aneurysm. Material and methods. The study was conducted in the Pathology Department of the Republican Research Center of Emergency Medicine (Tashkent, Uzbekistan) from January 2024 to September 2025. A total of 19 biological samples of aorta from patients with aortic aneurysms, from whom biological material was obtained intraoperatively, were studied. These included atherosclerotic lesions (n=9), Marfan syndrome (n=5), sinus of Valsalva rupture (n=3), and Takayasu syndrome (n=2). Histological preparations were examined using a Carl ZEISS Axiostar Plus microscope. Quantitative analysis was performed using Fiji by ImageJ software, and statistical analysis was conducted in SPSS 23.0. Results. In atherosclerosis, typical plaques with lipid cores, pronounced medial layer calcification, and cholesterol crystals were identified. In Marfan syndrome, focal destruction of elastic fibers in the tunica media and mucoid degeneration of the media with uneven accumulation of mucopolysaccharides were found. In sinus of Valsalva aneurysms, uneven thickness of collagen and reticulin fibers with pronounced edema of the middle layer was present. In Takayasu syndrome, inflammatory infiltration of the middle layer and marked reduction in smooth muscle fiber quantity were detected. Conclusion. Morphological examination of the aortic wall revealed significant differences in the structure and composition of wall components, confirming the heterogeneity of aortic aneurysm pathogenesis. Quantitative morphometric criteria for diagnosis verification were determined: elastic fiber density (&lt;20% characteristic of Marfan syndrome), inflammatory cell count (&gt;250/mm² specific for Takayasu arteritis), medial calcification (&gt;40% indicates atherosclerotic origin).</jats:p>