Hepatic adenoma is a very rare type of benign tumor that originates in the liver. Global frequency of this cancer is unknown; in the United States, there are just 1 to 1.3 cases per million people annually. This type of tumor is much more common in women than in men, at a ratio of 9 to 1, because women who have taken oral contraceptives have an increased risk of developing this cancer. Hepatic adenoma is also called hepatocellular adenoma or liver cell adenoma. This benign tumor has the potential to become cancerous at a rate of between 8 percent and 13 percent.
The main risk factor for hepatic adenoma is the use of oral contraceptives. In women who have used oral contraceptives for five to seven years, the risk is increased by a factor of five. Women who use oral contraceptives for nine years or more have a 25-fold increased risk of this liver tumor. Other risk factors include the use of anabolic steroids, and Type 1 diabetes.
The underlying cause of this type of tumor is not well understood, but it is known that hormones play a role. Even so, although both oral contraceptives and anabolic steroids are risk factors, these tumors sometimes can develop in children in the absence of any known risk factors. Another factor that might influence the development of these tumors is an imbalance in insulin and glucagons, the hormones that balance blood sugar levels and blood sugar uptake by cells.
The most common hepatic adenoma symptom is pain in the upper right portion of the abdomen. As much as 50 percent of people with this tumor will experience pain in this region. Large tumors might be noticeable as an abdominal growth. In some cases, the tumor is discovered only when medical imaging is carried out for another reason; sometimes, a patient has severe pain and abdominal bleeding that require emergency treatment. This latter situation is more likely to occur in women who are pregnant or menstruating or who are taking a high-dose oral contraceptive pill.
Because growth of this cancer is promoted by hormones, women with hepatic tumors should avoid pregnancy and further use of oral contraceptive pills. Use of anabolic steroids, if applicable, should also be stopped. Sometimes, this is enough to cause the tumor to stop growing and even reduce in size. Unfortunately, the risk of the tumor becoming malignant is not reduced even if the use of steroids or contraceptives is stopped.
Hepatic adenoma tumors that cause symptoms and tumors larger than 2 inches (5 cm) in size are almost always removed via surgery. The removal of large tumors is necessary even in the absence of symptoms because these tumors have an increased risk of hemorrhaging. People who are treated for this disease typically are monitored for tumor recurrence with annual ultrasound and blood tests.