An 11-year-old obese dog was referred for a liver mass. Cytologic examination revealed vacuolated hepatocytes with mild pleomorphism. A partial liver lobectomy was performed. On histopathologic examination, the mass was diagnosed as hepatocellular carcinoma composed of hepatocytes with clear vacuoles. These findings were consistent with clear cell hepatocellular carcinoma (CCHCC). The CCHCC is a rare subtype of hepatocellular carcinoma in dogs, and clinical features are poorly defined. This is the first report on the cytological, histological and clinical aspects of CCHCC, suggesting that obesity and hyperlipidemia are potential risk factors for CCHCC in dogs.

Two Domestic Korean Shorthair cats presented with dyschezia and vomiting. Computed tomography revealed a colonic mass with calcification and lymph node metastasis in case 1, and a small intestinal mass with disseminated mesenteric metastasis and calcification in case 2. Histopathology revealed intestinal adenocarcinoma with osseous metaplasia. Case 1 died two months after surgery from distant metastasis; and case 2 showed no metastasis for five months but presented with anorexia, euthanized seven months after diagnosis. Metastatic intestinal adenocarcinoma with bone formation should be considered as differential diagnosis for calcification on imaging, and lymph node metastasis at diagnosis may indicate poor prognosis.