Thursday 7 February 2013
hepatic maligant epithelial tumors; maligant epithelial tumors of the liver
hepatic maligant epithelial tumors
- hepatocellular carcinoma
- cholangiocellular carcinoma
- hepatic cystadenocarcinoma
- hepatic squamous cell carcinoma
Various factors are involved in the oncogenesis and progression of malignant liver tumors:
In chronic hepatitis and cirrhosis, the repeated cell division and turnover increases the rate of possible mutations and limits the time frame for chromosomal repair. The inflammation seen in chronic hepatitis can generate reactive oxygen species (e.g., nitric oxide, hydroxy radicals) that have mutagenic effects.
Tumor suppressor genes (e.g., p53, pRb) normally arrest cell cycles. In hepatocellular carcinoma, this regulatory process is inhibited, resulting in progressive and uncontrolled cell division.
Specific abnormalities such as allelic deletions and regional chromosomal losses and gains have been detected in malignant hepatic tumors.
Telomeres, normally seen at chromosomal ends, are known to shorten over time