Case Report: Clinical and pathological features of a metastasizing malignant mixed epithelial and stromal tumor of the kidney in a Siberian tiger (Panthera tigris altaica)
Year: 2025
Type: article
Study design: Case Report
Abstract: ) from the ZOO Ljubljana. The tiger presented with hematuria, and after unsuccessful treatment attempts with antibiotics, an ultrasound examination followed by laparotomy was performed. During the laparotomy, a large encapsulated lesion weighing 9.3 kg was found in the location of the left kidney and surgically removed. Histopathological examination of the lesion revealed an encapsulated tumor with a biphasic growth pattern consisting of mesenchymal and epithelial components. Numerous mitoses, hemorrhages, and necrosis were found in the mesenchymal component, which resembled ovarian stroma, leading to the diagnosis of malignant MEST of the kidney. After 3 months, the tiger clinically deteriorated and was euthanized after diagnostic imaging revealed multiple metastases. At necropsy, numerous metastases were found at the site of the previously excised tumor, at the laparotomy scar, in the peritoneum, liver, pancreas, omentum, mesentery, lungs, and sternal lymph nodes. Microscopically, the tumor lesions consisted only of the malignant mesenchymal component. To our knowledge, this is the first report of malignant MEST of the kidney with peritoneal seeding and distant metastases in animals.
Source: Frontiers in Veterinary Science
Authors: Tanja Švara, Mitja Gombač, Nika Kojc, Mojca Harej, Marjan Kastelic, Peter Kržan, Tamara Dolenšek, Pavel Kvapil
Institution: University of Ljubljana
Language: English
Topic: Veterinary Oncology Research
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7110853556