Minute scirrhous hepatocellular carcinomas undergoing different carcinogenetic processes.

Scirrhous hepatocellular carcinoma (scirrhous HCC) is a rare histological subtype of HCC characterized by marked fibrosis along the sinusoid spaces. Carcinogenetic processes and pathological features at earlier stages of scirrhous HCC remain unclarified. In the present report two cases of minute scirrhous HCC suggesting different carcinogenesis, are described. The first case involved a 54-year-old man with liver cirrhosis related to HCV infection. This patient died of ruptured splenic aneurysm. At autopsy a hepatic tumor measuring 1.8 cm was found, and this tumor had a nodule-in-nodule appearance. Histologically, the inner part of the tumor was well-differentiated HCC with prominent collagen fiber deposition along the sinusoids (scirrhous HCC), whereas the outer part was a high-grade dysplastic nodule. The other patient was a 75-year-old woman who died of hepatic failure due to liver cirrhosis probably related to non-alcoholic steatohepatitis. At autopsy a hepatic tumor (1.2 cm in diameter) was incidentally found in the cirrhotic liver, and was histologically scirrhous HCC without dysplastic nodule elements. Carcinoma cells proliferated along the cirrhotic fibrous septa and replaced regenerative nodules. These two cases suggested that scirrhous HCC could occur in dysplastic nodules (the former case) and also develop de novo in cirrhotic liver (the latter case).