Pheochromocytoma is an uncommon tumor of the adrenal gland. It has been described in domestic species, mostly in dogs1 but also in a variety of wildlife species.2 This tumor has been found in two middle-aged lionesses, within a time period of two months. Both lived in captivity in Lionrock Big Cat Sanctuary, were not related and euthanised. Diagnoses in both cases was made by macroscopical and histological findings. In the first case both adrenal glands were found to have undergone neoplastic changes, being enlarged, mottled and friable. Metastatic nodules were found in the lung, spleen, cerebrum as well as hemorrhages within the upper alimentary tract. Additionally multicentric pulmonary adenocarcinoma was found. In the second case only the left adrenal gland was highly enlarged, nodular encapsulated and invading into the vena cava cranially. The right adrenal gland showed adrenocortical atrophy. Metastatic masses were found in the liver, kidney and lung there was moderate bone marrow haematopoesis. No signs of hypertension could be identified as described in dogs and humans. Electron microscopy for confirmation of presence of nor/adrenaline granules hasn’t been done yet but is advised. Clinical signs were nonspecific as this is usually the case with pheochromocytomas, leaving up to 50% clinically undiagnosed. Regarding non-domestic cats this tumor was found in one tiger (Panthera tigris)3 in a German zoo and commonly described in captive clouded leopards (Neofelis nebulosa)1. The question of contributing factors still remains.
The author thanks Lionsrock Big Cat Sanctuary Staff and Four Paws.
1. Gilson et al., Pheochromocytoma in 50 Dogs, J Vet Intern Med, Vol 8, No 3 (May–June), 1994;8: 228–232.
2. Corner et al., Histologic and Immunohistochemical Characterisation of Pheochromocytomas in 20 Clouded Leopards (Neofelis nebulosa), Veterinary Pathology 2017, Vol. 54(2) 269–276.
3. Junginger et al. (2015) Pathology in Captive Wild Felids at German Zoological Gardens. PLoS ONE 10(6): e0130573. doi:10.1371/journal.pone.0130573.