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

## TL;DR

This study investigates intestinal emphysema in pigs, revealing that gas-filled cysts are linked to lymphatic issues and granulomas, similar to human cases.

## Contribution

The study provides new morphological evidence linking porcine intestinal emphysema to lymphatic-centered pathology and granuloma formation.

## Key findings

- Gas-filled cysts in pigs are mainly located in the submucosal and mesenteric layers.
- Cysts are partially lined by lymphatic endothelial cells and associated with granulomas.
- The findings suggest a lymphatic origin for the lesions, similar to human intestinal emphysema.

## Abstract

Intestinal emphysema is characterized by gas-filled cysts within the intestinal wall, and it is occasionally observed in slaughtered pigs. The etiology and pathogenesis of intestinal emphysema remain poorly understood. This study aimed to provide further morphological insights into porcine intestinal emphysema through histopathological, histochemical and immunohistochemical methods. Ten slaughtered heavy pigs were examined, showing gross lesions consistent with intestinal emphysema. Gaseous cysts were mainly located in the submucosal and mesenteric layers, at least partially lined by lymphatic endothelial cells, and almost invariably associated with granulomas. Overall, data suggests that porcine intestinal emphysema is a lymphatic-centered disorder of the intestinal wall and mesentery, showing pathological features very similar to those described in human medicine.

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.