Ohfuji S
Department of Histopathology, Diagnostic Animal Pathology Office, Hokkaido, Japan.
J Comp Pathol. 2014 Jul;151(1):80-2. doi: 10.1016/j.jcpa.2014.02.002. Epub 2014 Feb 11.
Epidermoid cysts were identified in the rumen of a 2-year-old Holstein-Friesian steer. Small nodules (<4 mm diameter) filled with paste-like, friable, white material were scattered in the rumen wall. Microscopically, the nodules were located in the submucosal connective tissue and comprised of cysts lined by stratified squamous epithelium surrounding keratin debris, exhibiting features identical to those of epidermoid cysts. The cysts were surrounded by chronic inflammation. The ruminal mucosa contained vesicles or cystic cavities filled by inflammatory exudate, in addition to empty cystic spaces lined by flattened endothelial cells, which were possibly of lymphatic origin. The development of these epidermoid cysts might have resulted from implantation of exfoliated squamous epithelial cells from damaged ruminal epithelium into the submucosal connective tissue, although the precise aetiology of this anomaly remains to be defined.
在一头2岁的荷斯坦-弗里生公牛的瘤胃中发现了表皮样囊肿。瘤胃壁上散在分布着一些小的结节（直径<4毫米），里面充满了糊状、易碎的白色物质。显微镜下，这些结节位于黏膜下结缔组织中，由内衬复层鳞状上皮的囊肿组成，囊肿周围有角质碎屑，呈现出与表皮样囊肿相同的特征。囊肿周围有慢性炎症。瘤胃黏膜除了有由扁平内皮细胞衬里的空囊腔（可能起源于淋巴管）外，还含有充满炎性渗出物的水疱或囊腔。这些表皮样囊肿的形成可能是由于受损瘤胃上皮脱落的鳞状上皮细胞植入到黏膜下结缔组织所致，尽管这种异常的确切病因仍有待确定。
