Hepatocellular Carcinoma in a Free-Ranging Three-Toed Sloth (<i>Bradypus variegatus</i>)

• Published in: Animals
• Main Authors: Alex Junior Souza de Souza, Andreza Pinheiro Malheiros, Victor Lopes da Silva, Tereza Cristina da Silva, Bruno Cogliati, Lilian Rose Marques de Sá
• Format: Article
• Language: English
• Published: MDPI AG 2022-07-01
• Subjects: liver; hepatic tumor; neoplasm; xenarthra; pilosa
• Online Access: https://www.mdpi.com/2076-2615/12/15/1921

The increasing interest of tumors in wildlife is important for biodiversity conservation and for monitoring environmental agents and/or contaminants with potential impact on human health. Here we described the occurrence of hepatocellular carcinoma (HCC) in noncirrhotic liver of a free-ranging three-toed sloth (<i>Bradypus variegatus</i>) from the Atlantic Forest biome in Brazil. The HCC showed a moderate mononuclear inflammatory infiltrate within the tumor tissue but with no inflammation and fibrosis in the adjacent liver tissue. Upon immunohistochemistry, neoplastic cells were diffusely positive for HepPar-1 and glutamine-synthetase presenting an irregular and random immunostaining pattern; β-catenin was positive in the cytoplasmic membrane of malignant hepatocytes; and cytokeratin 19 immunostaining was restricted to bile duct epithelial cells. The liver tissue was negative for HBV-like and HCV-like viruses assessed by molecular tests. The potential similarity of pathogenesis may reinforce the need for research on environmental and/or infectious agents associated with HCC that may contribute to the understanding of cancer in wildlife.