Brunner's gland hyperplasia in the sand rat (Psammomys obesus).

Brunner's glands are submucosal glands located in the proximal duodenum. Hyperplasia of the Brunner's gland has been reported rarely in humans and animals. We examined sections of the Brunner's gland from 63 sand rats submitted for necropsy over 2 years. Of the 63 animals necropsied, 45 (71%) had evidence of hyperplasia defined as nodular expansion, dilated ducts, or intraductal papillary proliferation. The hyperplasia was graded as mild in 22 (49%) of the cases, moderate in 15 (33%), and marked in 8 (18%). We found an association with both increased age and evidence of gastric ulceration and hyperplasia of the Brunner's gland. In sand rats with marked hyperplasia, 8 of 8 (100%) had evidence of gastric ulceration, compared to 13 of 18 (72%) in animals with no hyperplasia. Animals with marked hyperplasia were, on average, 8.4 months older than animals with no hyperplasia. There was no association with gender. The lesion in sand rats is histologically similar to that in humans.

Feline systemic reactive angioendotheliomatosis: eight cases and literature review.

A rare, multisystemic intravascular proliferative disorder was identified postmortem in eight cats. The majority of these cats died or were euthanized following episodes of dyspnea, lethargy, and anorexia. Microscopic examination revealed occlusive, intraluminal proliferations of spindle cells within small vessels. The heart was consistently involved, and myocardial dysfunction was the probable cause of illness in all cats. Immunohistochemically, the majority of intravascular cells expressed von Willebrand factor, and a smaller number expressed smooth muscle actin, compatible with a dual population of endothelial cells and pericytes, suggesting a reactive rather than a neoplastic process. Four cases of a similar feline vascular disorder from the veterinary literature are reviewed. The histopathology resembles reactive angioendotheliomatosis in humans, a benign cutaneous intravascular endothelial and pericytic proliferative condition. However, in contrast, this feline disease is multisystemic and fatal. We propose the name "feline systemic reactive angioendotheliomatosis" for this unique, idiopathic disorder of domestic cats.

An oral choristoma in a foal resembling hairy polyp in humans.

A neonatal foal was presented with a 6.5-cm pedunculated mass arising from the upper deciduous incisors. The distal end was soft and covered by haired skin, whereas the proximal end was firm, covered with mucosal epithelium, and at the point of transection contained a fully developed tooth. Microscopically, the mass was covered by epidermis and mucosal epithelium and the remaining portion of the mass consisted of mature collagen, nonneoplastic fat and smooth muscle, and a single tooth within a bony socket. The mass is consistent with an oral choristoma and has features similar to those described for hairy polyp in humans.