The liver is one of the largest organs in your body and lies in the upper right-hand side of your abdomen underneath your ribs. It has several very important functions including the manufacturing of proteins, the removal of toxins from your blood, aiding in metabolism of fats, proteins and carbohydrates and the secretion of bile, which helps digest foods.
Tumors are abnormal growths or masses. When a tumor is a cancer, it is called malignant. When a tumor is not a cancer, we call it benign. There are 3 main types of benign liver tumors. They are adenomas, hemangiomas and focal nodular hyperplasia (FNH). Of these, only adenomas have any risk of turning into a cancer. Cancer transformation by a liver adenoma is very rare and usually only happens when it has grown very large.
Liver hemangiomas and FNH have no known cause. The exact cause of liver adenomas is not known either but there is a significant association between adenomas and oral contraceptive use. For this reason, adenomas are most commonly diagnosed in women of child bearing age.
Most benign liver tumors do not have symptoms. Symptoms usually do not develop until the mass is so big that it pushes on other organs. When this happens, it can cause upper abdominal pain, particularly on the right side. If the tumor pushes on the stomach it can cause a sense of fullness after eating which limits the amount of food you can eat. If this goes on long enough, you may even experience unintentional weight loss. A rare complication from large adenomas is bleeding in the liver. This usually causes immediate intense right upper abdominal pain. This can be life threatening and patients with suspected rupture should be evaluated by a physician immediately.
Most benign liver tumors do not cause symptoms and are found incidentally on abdominal imaging studies such as an ultrasound, CT scan or MRI. It is important that benign tumors are not misdiagnosed. Your doctor may choose to follow the tumor with imaging studies to ensure that they have been diagnosed correctly. A biopsy may be required if the CT or MRI is unclear regarding the nature of the liver tumor.
If the tumor is not causing any symptoms, most tumors can be watched and followed with imaging studies. Tumors that do cause symptoms such as the ones describe above should be removed. This is usually done with surgery.
Surgery for benign liver tumors requires removing the tumor completely. This is called a liver resection. Occasionally this can be done in a minimally invasive fashion. The portion of liver that needs to be removed is determined based on the location of the tumor. The liver is a unique organ because it can regenerate (grow back) after surgery—even if up to 75% is removed.