Saito Tsubasa, Chambers James K, Nakashima Ko, Uchida Eri, Ohno Koichi, Tsujimoto Hajime, Uchida Kazuyuki, Nakayama Hiroyuki
1 Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyō, Tokyo, Japan.
2 Japan Small Animal Medical Center, Saitama, Japan.
Vet Pathol. 2018 Sep;55(5):654-662. doi: 10.1177/0300985818777798. Epub 2018 May 31.
Biopsy samples of colorectal polyps were collected and examined from 67 Miniature Dachshund dogs (including 35 cases with an additional biopsy). Histopathologic diagnoses of the initial biopsy samples were "inflammatory polyp" in 52 cases (78%), "adenoma" in 10 cases (15%), and "adenocarcinoma" in 5 cases (8%). Eight of 10 cases (80%) diagnosed as adenoma also had inflammatory polyp lesions in the same specimen. A second biopsy was performed in 25 cases (48%) initially diagnosed with inflammatory polyp. Pathologic diagnoses for the second biopsy were inflammatory polyp in 11 cases (44%), adenoma in 9 cases (36%), and adenocarcinoma in 5 cases (20%). The number of beta-catenin-positive nuclei in epithelial cells was significantly higher in adenoma (46%) and adenocarcinoma (75%) as compared with inflammatory polyp (6%). Normal epithelial cells and hyperplastic goblet cells in inflammatory polyps showed homogeneous positive cytoplasmic immunoreactivity for adenomatous polyposis coli (APC) antigen. However, APC expression was decreased in areas of intense nuclear beta-catenin expression in adenoma and adenocarcinoma lesions. Foci of cytokeratin 5/6-positive squamous cell-like neoplastic cells showed intense beta-catenin nuclear expression that was similar to squamous morules described in human colorectal tumors. The results of the present study suggest that the inflammatory polyp in Miniature Dachshunds is a progressive disease that may develop into adenoma and/or adenocarcinoma. In addition, immunohistochemical findings suggest that aberrations of APC and beta-catenin expression may be involved in tumor development within the inflammatory polyp lesions.
收集了67只迷你腊肠犬的大肠息肉活检样本并进行检查（其中35例进行了额外活检）。初始活检样本的组织病理学诊断为：52例（78%）为“炎性息肉”，10例（15%）为“腺瘤”，5例（8%）为“腺癌”。诊断为腺瘤的10例中有8例（80%）在同一标本中也有炎性息肉病变。对最初诊断为炎性息肉的25例（48%）进行了第二次活检。第二次活检的病理诊断为：11例（44%）为炎性息肉，9例（36%）为腺瘤，5例（20%）为腺癌。与炎性息肉（6%）相比，腺瘤（46%）和腺癌（75%）上皮细胞中β-连环蛋白阳性核的数量显著更高。炎性息肉中的正常上皮细胞和增生性杯状细胞对腺瘤性息肉病蛋白（APC）抗原显示均匀的细胞质阳性免疫反应。然而，在腺瘤和腺癌病变中，APC表达在β-连环蛋白强烈核表达区域降低。细胞角蛋白5/6阳性的鳞状细胞样肿瘤细胞灶显示强烈的β-连环蛋白核表达，类似于人类结直肠癌中描述的鳞状小结。本研究结果表明，迷你腊肠犬的炎性息肉是一种可能发展为腺瘤和/或腺癌的进行性疾病。此外，免疫组化结果表明，APC和β-连环蛋白表达异常可能参与炎性息肉病变内的肿瘤发生。
