Gastric adenocarcinoma as cause of death of a captive rock hyrax (Procavia capensis)

Abstract

The rock hyrax (Procavia capensis) is a medium-sized, terrestrial mammal which lives across Africa and the Middle East. In Croatia, the rock hyrax are found in two zoos. The pathology of these animals has been rarely investigated. So far, pathologic findings have been described in only one report on 111 adult captive rock hyrax from USA.
A captive rock hyrax was submitted for necropsy to our Department. No signs of disease were noted during the life of the animal. Necropsy revealed severe, generalized anemia of mucoses and subcutis. The stomach was filled with 500 ml of black mucous, while the mucosa was rough, white and with multiple round ulcerations measuring 1 to 3 mm. Histology of the stomach revealed mucinous gastric adenocarcinoma affecting the mucosa, submucosa and the muscular layer. The intestine was filled with black feces, the intestinal mucosa was unremarkable. On the dorsal lumbosacral part on the back, affecting the skin, subcutis and muscles was focally extensive, acute to subacute purulent Staphylococcus sp.-caused dermatitis. Other organs did not show gross nor microscopic pathologic lesions. Cause of death was determined as gastric adenocarcinoma with subsequent melena and anemia.
Pathology of rock hyrax is rarely described. The only paper reporting pathologic findings described neoplasia in ten of investigated animals, and gastric adenocarcinoma was diagnosed in only one animal. The paper suggests that rock hyrax are more resistant to oncogenic events due to low incidence of detected neoplasia. We describe another gastric adenocarcinoma, contributing to the scarce information about these animals.

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Correspondance: Doroteja Huber, Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Zagreb; Heinzelova 55, 10000 Zagreb, Croatia; email: dhuber@vef.hr; phone: +385 1 2390 310
Gastric adenocarcinoma as cause of death of a captive rock hyrax (Procavia capensis)
Doroteja Huber, Ivana Mihoković Buhin, Dunja Vlahović, Lidija Medven Zagradišnik, Marko Hohšteter, Branka Artuković, Ivan-Conrado Šoštarić-
Zuckermann, Andrea Gudan Kurilj
Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Zagreb
The rock hyrax (Procavia capensis)is a medium-sized, terrestrial mammal which
lives across Africa and the Middle East. In Croatia, the rock hyrax are found in two zoos.
The pathology of these animals has been rarely investigated. So far, pathologic findings
have been described in only one report on 111 adult captive rock hyrax from USA.
A captive rock hyrax was submitted for necropsy to our Department. No signs of
disease were noted during the life of the animal. Necropsy revealed severe, generalized
anemia of mucoses and subcutis. The stomach was filled with 500 ml of black mucous,
while the mucosa was rough, white and with multiple round ulcerations measuring 1 to 3
mm. Histology of the stomach revealed mucinous gastric adenocarcinoma affecting the
mucosa, submucosa and the muscular layer. The intestine was filled with black feces,
the intestinal mucosa was unremarkable. On the dorsal lumbosacral part on the back,
affecting the skin, subcutis and muscles was focally extensive, acute to subacute
purulent Staphylococcus sp.-caused dermatitis. Other organs did not show gross nor
microscopic pathologic lesions. Cause of death was determined as gastric
adenocarcinoma with subsequent melena and anemia.
Fig. 1. Opened stomach, rinsed with water: the
mucosa of the stomach was thickened, rough,
with multifocal to coalescing ulcerations. Pathology of rock hyrax is rarely described. The only paper reporting pathologic findings
described neoplasia in ten of investigated animals, and gastric adenocarcinoma was
diagnosed in only one animal. The paper suggests that rock hyrax are more resistant to
oncogenic events due to low incidence of detected neoplasia. We describe another gastric
adenocarcinoma, contributing to the scarce information about these animals.
Fig. 2. The mucosa is infiltrated by nests of
neoplastic cells separated by moderate amounts
of fibrous stroma. HE, 4x.
Fig. 3. Neoplastic cells are cuboidal to polygonal
with moderate pleomorphism and 1 mitosis in 10
HPF. There are rare binucleated cells and multifocal
necroses. HE, 10x.
Fig. 4. Occasionally, neoplastic cells form pools
filled with dense,eosinophilic fluid.HE, 10x.
Fig. 5. Fluid from Fig. 4 stains positive with
Periodic Acid-Schiff stain, corresponding to
mucin. PAS, 10x.