Primary epithelial tumors of the gallbladder are rarely reported in animals. In this study, 9 aged pigs (6-12 years old) were histopathologically examined for gallbladder proliferative lesions. At necropsy, a large gallstone occupied the lumen of the gallbladder of 3 pigs. Histopathological examination revealed chronic cholecystitis in all 9 pigs, mucosal hyperplasia in 2 pigs, adenoma in 1 pig, and adenocarcinoma in 2 pigs. Bacilli were detected in the gallbladder lumen of 6 pigs by Warthin-Starry stain. Mucosal hyperplasia, adenoma, and adenocarcinoma were characterized by papillary projections of the mucosa with occasional acinar structures. Tumor invasion of the surrounding tissue was observed in the cases of adenocarcinoma. On Alcian blue and periodic acid-Schiff double-stained sections, the acinar structure of gallbladder mucosa in chronic cholecystitis and mucosal hyperplasia was stained in a mosaic pattern, indicating pyloric gland metaplasia. The results of immunohistochemistry revealed a CD10-positive epithelial brush border and mucin (MUC) 2-positive goblet cells in chronic cholecystitis, adenoma, and adenocarcinomas, indicating intestinal metaplasia. Immunoreactivity of MUC5 AC and cytokeratin 19 was weaker in adenoma and adenocarcinomas compared with the normal and hyperplastic gallbladder mucosa. The number of p53-positive nuclei and the Ki-67 index were higher in adenocarcinomas compared with benign lesions. These results suggest that chronic cholecystitis associated with gallstones and/or bacterial infections may contribute to metaplastic changes and development of gallbladder tumors in aged pigs. Alteration of mucin, cytokeratin, and p53 profiles in gallbladder proliferative lesions in pigs were similar to that in humans, suggesting a common pathogenesis in tumor development.

中文翻译：

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老年猪胆囊的慢性炎性和增生性病变。

很少有动物报道胆囊原发性上皮肿瘤。在这项研究中，对9头年龄大的猪（6-12岁）进行了病理组织学检查，以了解胆囊增生性病变。尸检时，一块大胆结石占据了三头猪胆囊的内腔。组织病理学检查显示所有9头猪均为慢性胆囊炎，2头猪为粘膜增生，1头猪为腺瘤，2头猪为腺癌。Warthin-Starry染色法在6头猪的胆囊腔中检出了芽孢杆菌。粘膜增生，腺瘤和腺癌的特征是粘膜的乳头状突起，偶有腺泡结构。在腺癌的病例中观察到肿瘤浸润周围组织。在阿尔辛蓝和高碘酸-希夫双染色切片上，慢性胆囊炎和粘膜增生中胆囊粘膜的腺泡结构呈马赛克状染色，表明幽门化生。免疫组织化学结果显示慢性胆囊炎，腺瘤和腺癌中CD10阳性上皮刷缘和黏蛋白（MUC）2阳性杯状细胞，表明肠上皮化生。与正常和增生性胆囊粘膜相比，MUC5 AC和细胞角蛋白19的免疫反应性在腺瘤和腺癌中较弱。与良性病变相比，腺癌中p53阳性核的数量和Ki-67指数更高。这些结果表明，与胆结石和/或细菌感染有关的慢性胆囊炎可能会导致年老猪的胆囊肿瘤发生化生改变和发展。粘蛋白改变