The diffuse type is poorly circumscribed and infiltrates the portal veins, or the hepatic veins (rarely).Microscopically, the four architectural and cytological types (patterns) of hepatocellular carcinoma are: fibrolamellar, pseudoglandular (adenoid), pleomorphic (giant cell), and clear cell. In well-differentiated forms, tumor cells resemble hepatocytes, form trabeculae, cords, and nests, and may contain bile pigment in the cytoplasm. In poorly differentiated forms, malignant epithelial cells are discohesive, pleomorphic, anaplastic, and giant. The tumor has a scant stroma and central necrosis because of the poor vascularization. A fifth form – lymphoepithelioma like hepatocellular carcinoma – has also been described. Staging
BCLC Staging System
The prognosis of HCC is affected by the staging of the tumor and the livers function due to the effects of liver cirrhosis.A number of staging classifications for HCC are available. However, due to the unique nature of the carcinoma to fully encompass all the features that affect the categorization of the HCC, a classification system should incorporate tumor size and number, presence of vascular invasion and extrahepatic spread, liver function (levels of serum bilirubin and albumin, presence of ascites, and portal hypertension) and general health status of the patient (defined by the ECOG classification and the presence of symptoms).Of all the staging classification systems available, the Barcelona Clinic Liver Cancer staging classification encompasses all of the above characteristics. This staging classification can be used to select people for treatment.
The electrodes are inserted into the liver tumor under ultrasound image guidance using percutaneous, laparoscopic or open surgical approach. It is suitable for small tumors (<5 cm). RFA has the best outcomes in patients with a solitary tumor less than 4 cm. Since it is a local treatment and has minimal effect on normal healthy tissue, it can be repeated multiple times. Survival is better for those with smaller tumors. In one study, In one series of 302 patients, the three-year survival rates for lesions >5 cm, 2.1 to 5 cm, and ≤2 cm were 59, 74, and 91%, respectively. A large randomized trial comparing surgical resection and RFA for small HCC showed similar four-year survival and less morbidities for patients treated with RFA. Cryoablation is a technique used to destroy tissue using cold temperature. The tumor is not removed and the destroyed cancer is left to be reabsorbed by the body. Initial results in properly selected patients with unresectable liver tumors are equivalent to those of resection. Cryosurgery involves the placement of a stainless steel probe into the center of the tumor. Liquid nitrogen is circulated through the end of this device. The tumor and a half inch margin of normal liver are frozen to −190 °C for 15 minutes, which is lethal to all tissues. The area is thawed for 10 minutes and then refrozen to −190 °C for another 15 minutes. After the tumor has thawed, the probe is removed, bleeding is controlled, and the procedure is complete.