Liver cancer is a malignant tumor of this rather precious organ. All the liver cancers can be classified into primary and secondary and there is one more classification according to the cells that form the very tumor. In primary liver cancer the tumor cells originate from the tissues that make liver. On the other hand, secondary liver cancers are actually metastases, tumors that have spread from other parts of the body and which are made from cells that are normally not found in the liver. Apart from being divided into primary and secondary cancers, liver cancers may differ pathohistologically. For example, the tumor may originate from hepatocytes (liver cells) or it may consist of the cells that line the bile ducts. No matter what the origin of the cancer is, all liver cancers are considered serious and are very lethal. They are hard to treat and are usually diagnosed in later stages of the disease.
Primary Liver Cancers
As already mentioned primary liver cancer originates from tissues that are normally found in the liver. At one moment certain cells start multiplying rapidly and uncontrollably and they form a lump. Primary liver cancers include hepatocellular carcinoma, cholangiocarcinoma, hepatoblastoma and cancers that originate from the liver's blood vessels.
Hepatocellular carcinoma is the most common liver cancer in adults. It accounts for approximately 75% of all primary liver cancers. The tumor is made of hepatocytes. The very cancer can be in a form of one nodule or there are multiple nodules in different parts of the liver. In advanced stage of the disease hepatocellular carcinoma tends to spread to nearby lymph nodes and distant organs.
Cholangiocarcinoma is liver cancer made of cells that are normally found inside the liver bile ducts. If it starts in bile ducts of the liver it is classified as intrahepatic cholangiocarcinoma and if the cancer originates from bile ducts that are normally outside the liver the cancer is known as extrahepatic cholangiocarcinoma.
Hepatoblastoma is a rather rare cancer and it predominantly affects children and infants. The survival rate for this cancer is great if the tumor is diagnosed on time.
And finally, angiosarcomas or hemangiosarcomas are malignant tumors that may form inside the liver. They are very rare but highly invasive and aggressive. The disease progresses rapidly and some treatments may slow down the growth or spread of the tumor but in majority of cases the disease causes lethal outcome within a year after setting of the diagnosis.
Secondary Liver Cancers
Secondary liver cancers do not originate from the liver tissue. They are actually primary cancers of other organs and are via blood stream spread to the liver. Almost every cancer in the body can spread to the liver and give liver metastases. Still, this is most typical for lung, breast, colorectal and bone cancer.