Radiographic, ultrasonographic, and computed tomographic characteristics of an accessory liver lobe in a cat.

A 5-year-old male Norwegian Forest cat presented with increased hepatic serum biochemical parameters. Abdominal radiography showed an oval cranioventral mass and ultrasound revealed a mobile mass attached to one hepatic lobe. Computed tomography (CT) confirmed that the mass was attached to the right medial liver lobe. Differential diagnoses were an accessory liver lobe, benign neoplasia, and focal nodular hyperplasia. The mass was removed and histopathology confirmed the mass to be normal liver tissue. Accessory liver lobe should be included in the differential diagnosis of a mobile cranial abdominal mass with a similar ultrasonographic or CT appearance to the liver.

Gene expression of growth factors and growth factor receptors for potential targeted therapy of canine hepatocellular carcinoma.

The purpose of this study was to evaluate the gene expression of growth factors and growth factor receptors of primary hepatic masses, including hepatocellular carcinoma (HCC) and nodular hyperplasia (NH), in dogs. Quantitative real-time reverse transcriptase-polymerase chain reaction was performed to measure the expression of 18 genes in 18 HCCs, 10 NHs, 11 surrounding non-cancerous liver tissues and 4 healthy control liver tissues. Platelet-derived growth factor-B (PDGF-B), transforming growth factor-α, epidermal growth factor receptor, epidermal growth factor and hepatocyte growth factor were found to be differentially expressed in HCC compared with NH and the surrounding non-cancerous and healthy control liver tissues. PDGF-B is suggested to have the potential to become a valuable ancillary target for the treatment of canine HCC.

Contrast agent Gd-EOB-DTPA (EOB·Primovist®) for low-field magnetic resonance imaging of canine focal liver lesions.

Contrast-enhanced magnetic resonance (MR) imaging with a new liver-specific contrast agent gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA; EOB·Primovist®) was studied in 14 normal beagles and 9 dogs with focal liver lesions. Gd-EOB-DTPA accumulates in normally functioning hepatocytes 20 min after injection. As with Gd-DTPA, it is also possible to perform a dynamic multiphasic examination of the liver with Gd-EOB-DTPA, including an arterial phase and a portal venous phase. First, a reliable protocol was developed and the appropriate timings for the dynamic study and the parenchymal phase in normal dogs using Gd-EOB-DTPA were determined. Second, the patterns of these images were evaluated in patient dogs with hepatic masses. The optimal time of arterial imaging was from 15 s after injection, and the optimal time for portal venous imaging was from 40 s after injection. Meanwhile, the optimal time to observe changes during the hepatobiliary phase was from 20 min after injection. In patient dogs, 11 lesions were diagnosed as malignant tumors; all were hypointense to the surrounding normal liver parenchyma during the hepatobiliary phase. Even with a low-field MR imaging unit, the sequences afforded images adequate to visualize the liver parenchyma and to detect tumors within an appropriate scan time. Contrast-enhanced MR imaging with Gd-EOB-DTPA provides good demarcation on low-field MR imaging for diagnosing canine focal liver lesions.

CT characteristics of primary hepatic mass lesions in dogs.

Little information is available on the relationship between computed tomography (CT) imaging findings and the pathologic diagnosis of canine hepatic tumors. Our purpose was to clarify the characteristic features of CT findings in liver tumors in dogs. Data from 33 dogs with either a hepatocellular carcinoma, n = 14, hepatocellular adenoma, n = 14, or nodular hyperplasia, n = 5 were summarized from medical records. CT features for each histologic diagnosis were characterized and analyzed statistically. Common findings in hepatocellular carcinoma included central (79%, P = 0.0030) and marginal enhancement (93%, P = 0.00043) in the arterial phase, cyst-like lesions (93%), capsule formation (93%), and hypoattenuation in the portal (86%), and equilibrium phases (93%). Hepatic adenoma was characterized by a characteristic diffuse enhancement pattern during the arterial phase (57%, P = 0.013), which was also found in nodular hyperplasia (60%), but never in hepatocellular carcinoma. Nodular hyperplasia was less likely to have a capsule structure (20%, P = 0.0087). Mass size was significantly smaller in nodular hyperplasia than in hepatocellular carcinoma and hepatic adenoma (P = 0.0033 and 0.038, respectively). Hyperattenuation in the arterial and the portal phase i.e. contrast retention, was more frequent in hepatic adenoma than in the other groups (P = 0.037 and 0.037, respectively). Nodular hyperplasia was more frequently isoattenuating in the equilibrium phase (P = 0.043).

A case report of hepatocellular carcinoma and focal nodular hyperplasia with a myelolipoma in two chimpanzees and a review of spontaneous hepatobiliary tumors in non-human primates.

Spontaneous hepatobiliary tumors in non-human primates are uncommon. Here we report a case of hepatic carcinoma and a case of hepatic focal nodular hyperplasia (FNH) and myelolipoma in two captive chimpanzees. A 16-year-old male chimpanzee (4X0392) died after an 8-month history of hepatic amyloidosis and low-grade anemia. Necropsy findings included a hepatic neoplasm with highly pleomorphic hepatocytes arranged into irregular thickened trabeculae. The diagnosis was high-grade hepatocellular carcinoma. A second male chimpanzee (4X0080), 23 years of age, died suddenly of heart failure secondary to cardiomyopathy. An incidental finding at necropsy was a liver mass characterized by multinodularity, prominent fibrous septa, and biliary hyperplasia. These features were consistent with FNH. While 4X0392 had no history of experimental viral exposure, 4X0080 was vaccinated with inactivated hepatitis B virus, an attenuated hepatitis A virus, and was experimentally infected with hepatitis C virus and human immunodeficiency virus. A survey of the literature revealed 68 reported cases of hepatobiliary tumors in non-human primates, including 12 hepatocellular adenomas, eight cholangiocellular adenomas/cystadenomas, 22 hepatocellular carcinomas, seven cholangiocarcinomas, and seven gallbladder adenocarcinomas. The majority of reported cases have been in prosimians and Old World monkeys. Hepatic neoplasia is rare in chimpanzees. Only four hepatic neoplasms have been reported in chimpanzees, three of which were associated with viral hepatitis. FNH has not been previously described in any non-human primate.