The liver is a large organ located at the upper right portion of the abdomen. It has many functions, such as filtering and detoxifying the blood and making bile to aid in digestion. Imaging scans such as CT or MRI sometimes find a liver mass or masses, which may require further investigation in order to determine whether the mass needs to be treated or left alone.
Cysts
A cyst is a hollowed-out cavity that may be filled with fluid. They can be found in the liver or other organs, according to "Robbins and Cotran Pathologic Basis of Disease" by Dr. Vinay Kumar. Most do not cause symptoms unless they are very large. These masses in the liver are common, and increasingly so with age. Most of them do not need a further diagnostic workup because imaging can usually establish the diagnosis.
Blood Vessel Growths
A hemangioma is an abnormal formation or collection of blood vessels. These can occur in any organ, and may even be seen on the skin as a birthmark commonly called a "strawberry." In the liver, a cavernous hemangioma is a common cause of a liver mass, particularly in women. They are typically not treated unless they cause symptoms.
Benign Liver Tumor
Two examples of benign liver tumors are the hepatic adenoma and focal nodular hyperplasia. A hepatic adenoma is a benign tumor of the liver cells that is most common in women who have used oral contraceptive pills, according to "Harrison's Principles of Internal Medicine" by Anthony Fauci, M.D. Even though they are not cancerous, they are frequently removed surgically because there is a small risk of them turning into cancer or rupturing, which can cause internal bleeding. Focal nodular hyperplasia is also more common in women. It has no risk of turning into cancer and rarely ever ruptures, so it is generally not removed.
Infections
Some infections can cause liver masses to appear on imaging scans. An amoebic abscess is a liver mass caused by an amoeba, which is a multicellular parasite. People with an amoebic liver abscess usually have pain in their abdomen and fever, in addition to a liver mass. Infectious masses can also be caused by bacterial infections. These are called pyogenic abscesses.
Cancers
Liver masses can also be cancerous. The liver is a common site for the growth of metastatic cancer. These are cancers that have grown elsewhere in the body and shed cells into the blood or lymphatic system. The cells take up residence in other organs, such as the liver, and grow into masses. The liver cells can also become cancerous and grow a tumor called a hepatocarcinoma. If the bile duct cells grow a cancer, it is called a cholangiocarcinoma.
References
- "Robbins & Cotran Pathologic Basis of Disease"; Vinay Kumar et al; 8th Ed., 2009
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci et al; 17th Ed., 2008
