The liver is one of the most fascinating organs in our bodies. It serves a wide variety of functions, from producing proteins to storing vitamins and dealing with toxins in our blood. Diseases affecting the liver, therefore, manifest by a wide variety of symptoms that need some expertise to be diagnosed. Diseases from liver inflammation (hepatitis) to liver failure and cancer can occur. Liver cancer is not a rare disease and is the end result of many cases of chronic liver inflammation. Liver cancer is the nightmare of most patients with chronic hepatitis, but what is much less known are benign liver tumors. They are not rare, but what made them less known is that they are usually symptomless and are discovered accidentally when you undergo a test for another cause.
Tumors result when a specific cell type or a group of cell types begin replicating without control or with limited control over their division. The main difference between benign and malignant tumors is that benign ones never invade neighboring tissues nor organs and do not go anywhere else in the body. They also have anatomical boundaries and can’t grow outside their main organ.
Most common benign tumors of the liver
Any cell type in the liver can theoretically give rise to a benign tumor. However, common things are common, and the most common benign tumors are:
- Hemangioma: Hemangioma is a benign tumor of the cells lining the blood vessels. It is so common that it is estimated that one in every five people has it. It is usually symptomless and rarely causes pain unless it is large in size. If your doctor finds it by chance, they may leave it alone or advice you to follow up on it. It can rarely rupture if huge in size or cause problems in your blood cells. This is, however, very rare and shouldn’t make you worry. Hemangioma cannot turn into a malignant tumor.
- Focal nodular hyperplasia: Focal nodular hyperplasia is the second commonest benign tumor after hemangioma. It usually occurs in females and rarely causes symptoms. It is also impossible for it to turn into cancer. Your doctor will only treat it surgically if it causes symptoms. It can shrink in some people after 40.
- Nodular regenerative hyperplasia: Nodular regenerative hyperplasia is the third most common benign tumor of the liver. It is not cancerous and cannot turn into cancer. However, it can occur in response to many stimuli including chemotherapeutic agents used to treat cancer and, in rare cases, some blood cancers. It can be symptomatic in a group of people and can cause jaundice. In such cases, surgery becomes a must.
- Hepatocellular adenoma: Although hepatocellular adenoma is the least common of the four, it remains the most widely known. This is because it is the most troublesome. Hepatocellular adenoma occurs in about one in a million humans and is closely linked to the use of oral contraceptive pills. Women who have been diagnosed with it are instructed to seek another method of contraception since the pills can enlarge it. Hepatocellular adenoma can rupture in some cases especially during pregnancy and has a probability of turning into cancer (hepatocellular carcinoma).
Other less common benign tumors exist including hamartoma, lipoma and angiomyolipoma. The first occurs when different tissues are organized haphazardly whether before or after birth, the second arises from fat cells and the third from fat cells and cells lining the blood vessels. Hepatic cysts are fluid-filled spaces that can occur within the liver or the biliary system. They are usually rare and of little significance except for cystadenomas which are considered as both cysts and benign tumors and have a risk of turning into cancer.