Hepatocellular carcinoma overview

# Overview
Hepatocellular carcinoma (HCC, also called hepatoma) is a primary malignancy (cancer) of the liver. The majority of hepaticellular carcinoma cases are due to either a viral hepatitis infection (hepatitis B or C) or cirrhosis (alcoholism being the most common cause of hepatic cirrhosis). In countries where hepatitis is not endemic, most malignant cancers in the liver are not primary hepatocellular carcinoma and the majority of cases are metastasis from other part of the body, e.g. the colon. Treatment options of hepatocellular carcinoma and prognosis are dependent on many factors, especially on tumor size and staging.
In non-western countries, the usual outcome is poor, because only 10 - 20% of hepatocellular carcinomas can be removed completely using surgery. If the cancer cannot be completely removed, the disease is usually deadly within 3 to 6 months. This is partially due to late presentation with large tumours, but also due to the lack of medical expertise and facilities. This is a rare tumor in the United States.

# Historical Perspective
Hepatocellular carcinoma was first noted to be associated with hepatitis B infection in 1970.

# Pathophysiology
On microscopic histopathological analysis, large polygonal tumours cells with graunular eosinophilic cytoplasm or layered dense collagen bundles are characteristic findings of hepatocellular carcinoma.

# Causes
Common causes of hepatocellular carcinoma include hepatitis B, hepatitis C, alcoholic liver cirrhosis, hemochromatosis, and hepatic porphyrias.

# Differentiating Hepatocellular Carcinoma from other Diseases
Hepatocellular carcinoma must be differentiated from other diseases that cause abdominal pain, jaundice, and weight loss, such as hepatitis B, hepatitis C, liver cirrhosis, and pancreatitis.

# Epidemiology and Demographics
Hepatocellular carcinoma is the 5th most common tumor worldwide. The epidemiology of hepatocellular carcinoma exhibits two main patterns, one in North America and Western Europe and another in non-Western countries, such as those in Sub-Saharan Africa, Central Asia and Southeast Asia, and the Amazon basin. Men are more affected than women and it is more common between the 3rd and 5th decades of life. Hepatocellular carcinoma causes 662,000 deaths worldwide per year.

# Risk Factors
Common risk factors in the development of hepatocellular carcinoma are chronic hepatitis B, chronic hepatitis C, cirrhosis, and inherited metabolic diseases.

# Screening
According to the American Association of Liver Diseases recommendations, screening for hepatocellular carcinoma by ultrasound (US) is recommended among patients with hepatitis B, hepatitis C, and cirrhosis. Screening is also recommended for Asian men over the age of 40, Asian women over the age of 50, and African American.

# Natural History, Complications and Prognosis
The majority of hepatocellular carcinomas present with advanced disease because the symptoms tend to occur later in the course of the disease. Without treatment, the patient will develop symptoms of jaundice, ascites, right upper quadrant abdominal pain, nausea, and vomiting, which will eventually lead to death. There are a variety of complications associated with hepatocellular carcinoma such as jaundice, ascites, cachexia, and coagulopathy. Depending on the extent of the tumor at the time of diagnosis, the prognosis may vary. However, the prognosis is generally regarded as poor. If the cancer is inoperable, the disease is usually deadly within 3 to 6 months.

# Diagnostic Studies

## Staging
According to the TNM staging system, there are four stages of hepatocellular carcinoma based on the tumor size, lymph node involvement, and distant metastasis.

## Diagnostic study of choice
Hepatocellular carcinoma is best diagnosed on a core biopsy of the liver. Core biopsy is done in a single visit at the hospital.

## History and symptoms
The majority of patients with are asymptomatic hepatocellular carcinoma during the early stages of the disease. Symptoms of hepatocellular carcinoma include abdominal pain, nausea, vomiting, weakness, jaundice, pruritus, splenomegaly, fatigue, hematemesis, fever, and loss of appetite.

## Physical examination
Patients with hepatocellular carcinoma usually appear cachectic. Physical examination of patients with hepatocellular carcinoma is usually remarkable for jaundice, pruritus, ascites, splenomegaly, esophageal varices, and cachexia.

## Laboratory findings
An elevated concentration of serum alpha-fetoprotein (AFP) may be helpful in the diagnosis of hepatocellular carcinoma.

## X-Ray
Performing chest x-ray might be helpful in detection of hepatocellular carcinoma metastasis to the lungs or to detect pleural effusion.

## Abdominal CT
Abdominal CT scan with intravenous contrast agent is the best method to diagnose hepatocellular carcinoma.

## Abdominal MRI
MRI may be helpful in the diagnosis of hepatocellular carcinoma.

## Abdominal ultrasound
Ultrasound may be helpful in the diagnosis of hepatocellular carcinoma.

## Other imaging studies
Hepatic angiography maybe helpful in the diagnosis of hepatocellular carcinoma. Hepatic angiography may show early opacification of the portal vein, filling defects in the hepatic venous system, and Portal vein tumor thrombus.

## Other diagnostic studies
Other diagnostic studies for hepatocellular carcinoma include laparoscopy and biopsy.

# Treatment

## Medical therapy
Patients with hepatocellular carcinoma are treated with ethanol injections, transcatheter arterial chemoembolization (TACE), sealed source radiotherapy, radiofrequency ablation (RFA), intra-arterial iodine-131-lipiodol administration, high intensity focused ultrasound (HIFU), hormonal therapy, and chemotherapy.

## Surgery
The feasibility of surgery depends on the stage of hepatocellular carcinoma at time of diagnosis.

## Primary prevention
Hepatitis B vaccine is recommended for all children to prevent the development of hepatitis B, which is a major risk factor for hepatocellular carcinoma. Other primary pr
evention strategies include abstinence from alcohol and screening for hemochromatosis.