Unveiling Intestinal Emphysema in Pigs: Morphological Insights and Pathogenetic Implications.

Intestinal emphysema is a rare pathological condition observed in humans and animals, characterized by the presence of multiple gas-filled cysts within the intestinal wall. In pigs, it is occasionally observed at slaughter, without affecting carcass suitability for human consumption or impairing farm profitability. Despite investigations, the etiology and pathogenesis of intestinal emphysema remain poorly understood. Therefore, this study aimed to provide further morphological insights into porcine intestinal emphysema through histopathological, histochemical and immunohistochemical methods. A total of ten slaughtered heavy pigs were examined, showing gross lesions consistent with intestinal emphysema. Gaseous cysts were predominantly located in the submucosal and mesenteric layers, at least partially lined by lymphatic endothelial cells. The cysts were separated by fibrous connective septa and were almost invariably associated with granulomas, consisting of epithelioid macrophages and multinucleated giant cells. Overall, the immunohistochemical patterns of porcine intestinal emphysema overlap with those described in humans and support the hypothesis that lesions likely originate within the lymphatic vessels.