Hepatocellular carcinomas in Vietnamese pot-bellied pigs (Sus scrofa)

Abstract

Various neoplasms have been reported in Vietnamese pot-bellied pigs ( Sus scrofa) with few reports of hepatocellular tumors. Twenty-two pot-bellied pigs diagnosed with hepatocellular carcinoma at necropsy over a 3-year period at one institution are described, representing 29% of the total pot-bellied pigs necropsied. The average age of affected pigs was 16.6 years with 15 males and 7 females. The most common clinical signs were decreased appetite (16/22) and weight loss (7/22). Grossly, the majority were massive tumors (13/22) with fewer nodular tumors (8/22) and 1 diffuse tumor. Massive tumors were typically multilobulated, very large, and encompassing 1 or more adjacent liver lobes, and were soft to firm and tan-yellow to orange-brown. Nodular tumors had multiple, 1–15 cm in diameter, discrete nodules in multiple liver lobes. Gross evidence of abscesses, necrosis, hemorrhage, or cysts associated with the tumor was occasionally described. Half of the cases had possible intrahepatic metastasis, and extrahepatic metastasis was identified in 3 cases, including to the hepatic lymph node (1/3), lung (2/3), spleen (1/3), and kidney (1/3). Histologically, all tumors had a trabecular or solid pattern, or a combination. An adenoid pattern was only identified in small regions of a few tumors. The neoplastic cells were relatively well-differentiated with moderate pleomorphism and a low mitotic index. Other histologic features within the tumors included intracellular glycogen or lipid accumulation, extramedullary hematopoiesis, foci of coagulative necrosis, and bile stasis. Aged pot-bellied pigs can be predisposed to hepatocellular carcinomas, which are locally aggressive and can metastasize within the liver and to other organs.

Neoplasmas em suínos: 37 casos

“…A população de suínos estudada reflete somente animais destinados à produção de carne e seus derivados, visto que não há relatos de suínos criados como animal estimação na região deste estudo. Atualmente, a grande maioria dos trabalhos descritos para tumores nesta espécie são referentes a suínos criados como animal de estimação, principalmente os Vietnamese pot-bellied pigs (Sus scrofa) (Munday & Stedman 2002, Haddad & Habecker 2012, Hirata et al 2014. Esta raça não é encontrada no Brasil, onde a criação de suínos como animais pet é extremamente recente.…”

“…Macroscopicamente, as lesões podiam ser observadas em todo o parênquima hepático e eram branco-amareladas ou avermelhadas. Apesar de haver descrição de tumores únicos, massas difusas pelo parênquima hepático predominam nas descrições do carcinoma hepatocelular em suínos (Haddad & Habecker 2012, Newman & Rohrbach 2012. Histologicamente a proliferação era semelhante à descrita para seu correspondente benigno, porém com pleomorfismo moderado a acentuado.…”

“…Neoplasmas hepáticos são descritos em suínos criados como pets, que morreram em consequência da doença, com uma média de idade de 15,5 anos (Haddad & Habecker 2012, Newman & Rohrbach 2012.…”

“…Nos últimos dez anos, entretanto, a prevalência de neoplasmas em suínos, principalmente naqueles criados como animais de companhia, aumentou consideravelmente (Newman & Rohrbach 2012) e apareceram vários relatos de tumores antes considerados raros para a espécie: glanglioneuroma no intestino delgado (Murakami et al 2011), carcinoma hepatocelular (Haddad & Habecker 2012), feocromocitoma maligno (Martínez et al 2011b), mastocitoma cutâneo, leiomioma/leiomiossarcoma, carcinoma de células escamosas e plasmocitoma (Newman & Rohrbach 2012).…”

Will donor‐derived neoplasia be problematic after clinical pig organ or cell xenotransplantation?

“…Primary liver malignancy is rare in young pigs . However, hepatocellular carcinomas have been reported in Vietnamese pot‐bellied pigs, but generally do not develop until the pig is old, with an average age of presentation being 16 years . The most common clinical signs are decreased appetite and weight loss.…”