Lesions on the Liver

The term lesion refers to any abnormal growth on the surface of an organ. Liver lesions can arise due to a variety of factors like infections, hormonal imbalances, congenital defects, cancerous growths, etc. Individuals with liver lesions may experience abdominal pain or may remain asymptomatic depending on the precise etiology, stage and type of lesion.

Liver lesions may comprise solid masses called tumors or may develop as fluid-filled sacs called cysts. They may be benign or malignant (cancerous) depending on the type of cells that form the lesion. Most liver lesions are benign, and may not be associated with any liver disease. However, some may be benign initially and grow malignant owing to several factors.

In most cases, benign lesions do not lead to any symptoms or health issues. However, abdominal pain is one of the most common symptoms in all types of liver lesions. A feeling of fullness may be experienced if large lesions are present.

It may be accompanied with nausea and vomiting. These symptoms are often assumed to be a result of minor digestive problems, and are simply ignored.

Larger tumors may be felt as a palpable mass in the upper right region of the abdomen. Complications arise rarely when the tumor affects surrounding tissues and blood vessels. Occasionally, the lesions may rupture and bleed thereby mildly affecting liver function.

Malignant tumors and cirrhotic lesions, on the contrary, may lead to extensive tissue damage which is manifested through jaundice and severe abdominal pain, in addition to the above symptoms. They are often diagnosed in the advance stages, and may even lead to liver failure.

Benign or noncancerous lesions are composed of cells that do not have the ability to migrate (metastasize) and cause lesions in other body organs. Such liver lesions include:

A buildup of normal and abnormal blood vessels due to an overgrowth of endothelial cells, that line the blood vessels, is termed as hemangioma. Such overgrowth occurs during the gestational period or during the first few months of life.

Liver hemangiomas or hepatic hemangiomas are about 4 cm wide and are present in about 22% of the population. They rarely grow, and their presence or growth generally does not affect liver functions. These benign tumors generally do not transform into malignant growths.

Benign tumors that originate from glandular tissues are termed as adenomas. Liver adenomas are more common in young women of child-bearing age, and are associated with hormonal changes due to endocrine disorders and use of oral contraceptives.

They may grow up to 15 cm wide, and may be felt as a palpable mass in the abdomen. At this size, they may rupture or damage the surrounding blood vessels and tissues. Individuals with adenomas are generally advised to opt for destruction or removal of the tumor, since they are at a risk for developing adenocarcinoma, the malignant counterpart of adenoma.

These small lesions on the liver comprise several cell types including hepatocytes, bile duct cells and blood vessels. They appear as solitary or multiple nodules in certain individuals.

The central portion of each nodule consists of small fibrous tissue bands and bile duct elements, that look like a radial scar during imaging tests. This rare lesion predominantly occurs in premenopausal women, and is also associated with the use of hormonal contraceptives.

This rare benign lesion involves a group of hepatocytes that transform into regenerative nodules. Unlike FNH, these lesions do not have fibrosis in or around the nodules. They generally occur in individuals above 60 years of age. The presence of such nodules may lead to portal hypertension (increase in blood pressure in the portal veins of the liver).

It is characterized by an unequal deposition of fat in the hepatocytes present in a particular region of the liver. It is common amongst diabetics, alcoholics, obese individuals and those with chronic liver diseases, protein energy malnutrition and anoxia.

Although mild fatty change does not affect liver functions, excessive accumulation of fat in the hepatocytes may lead to cell death.

Also known as congenital hepatic cyst, it refers to a cystic lesion that develops in the liver during the gestational period. It is the result of anomalies in development of the bile duct regions that are present within the liver. Such abnormally formed bile ducts lack connection to the main biliary duct/tree resulting in an accumulation of fluid and cyst formation.

This condition refers to the cystic transformation and enlargement of the bile duct, and may be congenital or develop in the later stages of life. These cysts are known to have a malignant potential and develop into cholangiocarcinoma (a type of bile duct cancer).

This inheritable disease is characterized by the presence of more than 20 cysts that are spread throughout the liver. In most cases, PLD is accompanied with the presence of multiple cysts in the kidney (polycystic kidney disease). It is more common in women, and the number of cysts increases with age.

Microbial infections that spread to the liver may lead to development of pus-filled lesions called abscesses. Such lesions are accompanied with fever, inflamed and palpable liver, anorexia and weight loss. Depending on the type of microbe involved, these are classified as:

» Pyogenic abscess: formed in case of bacterial infections like Staphylococcus aureus, Klebsiella pneumoniae,Streptococcus spp., Escherichia coli and other enterics.
» Amoebic abscess: develop in response to Entamoeba histolytica infection.
» Fungal abscess: observed in case of fungal infections like candidiasis.

Many parasitic worms like Echinococcus spp. (hydatid cysts), common liver fluke or Fasciola hepatica and giant liver fluke or Fascioloides magna, live and/or multiply in the liver by forming membrane-bound lesions in the hepatic and biliary tissues.

These lesions are termed parasitic lesions, and are accompanied with liver inflammation as well as disruption in liver morphology. Severity of the condition depends on the size and number of parasites, their duration in the liver, as well as their life cycle.

Malignant growth in the liver tissues, may occur spontaneously from abnormal liver cells or from cancerous cells that have metastasized from tumors present in other body organs.

Hepatocellular carcinoma and hepatoblastoma are two primary liver cancers that involve the development of malignant tumors. Metastatic lesions in the liver can arise due to any type of cancer, but are more commonly observed in case of bile duct cancers, gastrointestinal cancers, breast cancer and melanoma.

Lesions on the liver are often diagnosed serendipitously while assessing other health concerns. They are detected through imaging techniques like computed tomography (CT), magnetic resonance imaging (MRI) and radiological diagnostic methods. 

A biopsy is advised in order to evaluate malignancy. Microbial and parasitic infections are confirmed through blood, urine and stool analysis for the presence of pathogens or pathogenic determinants.

Benign, asymptomatic lesions may require no specific therapy, whereas large lesions may be removed by minimally invasive techniques like laparoscopy as well as surgical procedures involving resection in severe cases.

Simple liver cyst is generally treated by marsupialization that involves the surgical creation of a drainage route for the cystic contents, to avoid fluid buildup.

The treatment prescribed for microbial infections involves the use of antibiotics, anthelmintics (drugs that act against helminths) as well as the surgical removal of cysts, in severe cases. Malignant growths may be destroyed using chemotherapy, laser therapy and radiofrequency ablation (RFA) or removed surgically. If extreme tissue damage has occurred, liver transplant may be advised.

Lesions on the liver are not always life-threatening, however, timely diagnosis and appropriate treatment for the same is essential to avoid any impending health issues and complications.

Disclaimer: This post is for informative purposes only, and should not be used as a replacement for professional medical advice.