Colonic mucinous adenocarcinoma in a tufted deer: differential diagnosis and literature review

An 18-y-old female tufted deer (Elaphodus cephalophus) had a short history of chronic diarrhea, progressive weight loss, and hindlimb instability. Given the poor prognosis, the deer was euthanized and submitted for postmortem examination. The most significant gross finding was segmental and multinodular mural thickening of the proximal colon. On cut surface of the affected colonic segments, 0.5-2-cm diameter, intramural, multiloculated, cystic structures containing gray, translucent, gelatinous material elevated the edematous mucosa. Microscopically, the intramural cystic structures were filled with mucinous matrix admixed with foamy macrophages, and lined by discontinuous segments of well-differentiated columnar, pancytokeratin-positive epithelium with basilar nuclei. Multifocally, transition was observed from hyperplastic mucosal crypt epithelium to dysplastic or neoplastic columnar and flattened epithelium lining submucosal and serosal cysts. Cyst lumina were irregularly disrupted by polypoid ingrowths of collagenous tissue covered by attenuated epithelium. Based on these findings, we diagnosed a well-differentiated mucinous adenocarcinoma. Although intestinal adenocarcinomas have been described in humans and animals, they are considered uncommon in most domestic species, except for sheep, for which genetic and environmental factors appear to influence occurrence. Our report addresses the knowledge gap regarding intestinal adenocarcinomas affecting cervids and specifically the tufted deer, a less-studied, near-threatened Asian cervid.

Intestinal Myxoid Leiomyosarcoma in a Sambar Deer (Rusa unicolor)

A 9-year-old male sambar deer (Rusa unicolor) that died during sedation had a large and firm polypoid mass, which expanded the small intestinal wall and partially obstructed the duodenal lumen. Histopathology revealed a pleomorphic sarcoma composed of stellate to spindloid cells loosely arranged in an abundant myxoid matrix. The cytoplasm of the neoplastic cells was strongly immunopositive for vimentin and smooth muscle actin, but negative for c-KIT, desmin and myoglobin. The findings are consistent with intestinal myxoid leiomyosarcoma, which is rare in cervids and has not been described in the sambar deer, which is an endangered species.

The role of bracken fern illudanes in bracken fern-induced toxicities

Bracken fern is carcinogenic when fed to domestic and laboratory animals inducing bladder and ileal tumours and is currently classified as a possible human carcinogen by IARC. The carcinogenic illudane, ptaquiloside (PTQ) was isolated from bracken fern and is widely assumed to be the major bracken carcinogen. However, several other structurally similar illudanes are found in bracken fern, in some cases at higher levels than PTQ and so may contribute to the overall toxicity and carcinogenicity of bracken fern. In this review, we critically evaluate the role of illudanes in bracken fern induced toxicity and carcinogenicity, the mechanistic basis of these effects including the role of DNA damage, and the potential for human exposure in order to highlight deficiencies in the current literature. Critical gaps remain in our understanding of bracken fern induced carcinogenesis, a better understanding of these processes is essential to establish whether bracken fern is also a human carcinogen.

SMALL INTESTINAL ADENOCARCINOMA WITH CARCINOMATOSIS IN A SWIFT FOX (VULPES VELOX)

A 7-yr-old, intact, female swift fox (Vulpes velox) presented to the Veterinary Health Center at Kansas State University with a history of chronic weight loss, lethargy, inappetence, and myiasis. On physical examination, a firm mass was palpated in the mid- to cranial abdomen. The fox was euthanatized as a result of the grave prognosis. Gross necropsy and histologic findings included a small intestinal adenocarcinoma with diffuse transperitoneal spread throughout the abdominal cavity (carcinomatosis). To the authors' knowledge, this is the first report of intestinal adenocarcinoma with carcinomatosis in a swift fox.

Ptaquiloside, the major carcinogen of bracken fern, in the pooled raw milk of healthy sheep and goats: an underestimated, global concern of food safety

Bracken fern (Pteridium aquilinum) is a worldwide plant containing toxic substances, which represent an important chemical hazard for animals, including humans. Ptaquiloside, 1, a norsesquiterpenoid glucoside, is the major carcinogen of bracken detected in the food chain, particularly in the milk from farm animals. To date, ptaquiloside has been shown in the milk of cows feeding on a diet containing bracken fern. This is the first study that shows the systematic detection of ptaquiloside, 1, and reports its direct quantitation in pooled raw milk of healthy sheep and goats grazing on bracken. Ptaquiloside, 1, was detected by a sensitive method based on the chemical conversion of ptaquiloside, 1, into bromopterosine, 4, following gas chromatography-mass spectrometry (GC-MS) analysis. The presence of ptaquiloside, 1, possibly carcinogenic to humans, in the milk of healthy animals is an unknown potential health risk, thus representing a harmful and potential global concern of food safety.