Hepatic adenoma

　　The true cause of hepatic adenoma is unknown, and the onset may be related to sexual endocrine disorders. Infantile cases may be related to congenital abnormalities in embryonic development. Henson believes that acquired factors may be closely related to liver cirrhosis and nodular hyperplasia of liver cells. Currently, it is widely believed that oral contraceptives are the main acquired cause of hepatic adenoma. It is now considered that its occurrence is closely related to oral contraceptives. In the 1950s and 1960s when oral contraceptives were not widely used, this disease was rare. More than 90% of patients with hepatic adenoma are young women, and at least 75% of patients have a history of taking contraceptives. The risk of disease in women over 30 who take contraceptives increases; the incidence of hepatic adenoma is directly related to the duration and dose of taking contraceptives. Tumor shrinkage can be seen after stopping the use of contraceptives; tumor enlargement can be seen during pregnancy; it is rare for post-menopausal women to have hepatic adenoma. Male hepatic adenoma may be related to diabetes, glycogen storage disease, and the use of androgens.

　　The most serious complication of hepatic adenoma is intra-abdominal hemorrhage, which requires emergency treatment. If not treated promptly, it may lead to a decrease in blood volume and shock. When the tumor ruptures and bleeds, the patient may experience sudden severe pain in the upper right abdomen, and severe cases may have hemorrhagic shock. HCA has the potential to transform into hepatocellular carcinoma. If conditions permit, it is recommended to undergo surgical treatment and regular follow-up abdominal CT scans.

　　The clinical manifestations of hepatic adenoma vary with the size, location, and presence of complications of the tumor. 5% to 10% of patients have no symptoms at all, which are accidentally found during physical examination or surgery. About 1/3 of patients with hepatic adenoma have abdominal mass and recent upper right abdominal pain, which may be hidden pain, accompanied by nausea, anorexia, and other discomforts; however, when the tumor ruptures and bleeds, the patient may experience sudden severe pain in the upper right abdomen, physical examination may show muscle tension, local tenderness, rebound pain, and in severe cases, hemorrhagic shock. Jaundice and fever are occasionally seen, and it should be noted that HCA not only has a tendency to rupture and hemorrhage but also has the potential to transform into hepatocellular carcinoma. There may be no symptoms in the early stage, and clinical signs will appear only when the tumor grows to a certain size:

　　1. Abdominal mass type

　　This type is more common. Patients often have no symptoms other than the discovery of an upper abdominal mass. During physical examination, the tumor can be palpated, with a smooth surface, hard texture, and usually no tenderness. The mass moves up and down with respiration. If it is a cystadenoma, there may be a cystic sensation during palpation. When the mass gradually increases and compresses adjacent organs, symptoms such as upper abdominal fullness, discomfort, nausea, and hidden pain in the upper abdomen may occur.

　　2. Acute abdominal syndrome type

　　Adenomas are supplied by a single artery, and the artery generally has no connective tissue support. Hemorrhage within the tumor often occurs, sometimes leading to capsule rupture. A study shows that 50% of patients have experienced acute hemorrhage within the adenoma, with a mortality rate of 6%. Larger lesions have a higher risk of hemorrhage than smaller ones. When there is intratumoral hemorrhage, patients may have sudden right upper quadrant abdominal pain, accompanied by nausea, vomiting, fever, etc. During physical examination, there may be right upper quadrant muscle tension, tenderness, and rebound tenderness. It is often misdiagnosed as acute cholecystitis and surgery is performed, only to find liver adenoma during surgery. Tumor rupture causes intraperitoneal hemorrhage, and patients may have severe right upper quadrant abdominal pain, tenderness, and rebound tenderness, and may have peritoneal irritation symptoms such as abdominal tenderness and rebound tenderness. Severe cases may cause shock due to excessive hemorrhage.

　　It is currently believed that HCA in women is closely related to oral contraceptives; in men, it is related to diabetes, glycogen storage disease, and the use of androgens. Therefore, prevention based on clear etiology is currently the key to preventing this disease. For young and middle-aged women of childbearing age who often take oral contraceptives, regular liver examinations should be performed to dynamically observe changes in liver morphology. Once liver space-occupying lesions are found, oral contraceptives should be discontinued first, and the changes in the tumor should be closely observed. If the tumor continues to grow, surgical treatment should still be sought. For those who have taken oral contraceptives for a long time, regular liver function tests should be performed.

　　Liver adenoma patients often have normal liver function tests or show mild elevation of GGT or ALP, and negative AFP. If AFP is elevated, it often suggests malignant transformation of liver adenoma.

　　1. Ultrasound examination

　　Ultrasound examination shows clear boundaries of the lesion, with echo depending on the surrounding liver tissue, as a low-echo mass. If there is hemorrhage and necrosis inside, it shows mixed echo, with clear boundaries and no halo.

　　2. CT scan without contrast

　　CT scan shows low-density areas in tumors, which can display different densities after enhancement. Enhanced CT shows that adenomas are generally isodense or slightly low in density. Due to the rich blood supply of adenomas, it is easier to detect adenomas in the arterial phase of contrast. In patients with glycogen storage disease or other conditions leading to fat infiltration, tumors can appear as high density, central necrosis, and occasionally calcification is also obvious. Tumor hemorrhage appears as high density on non-enhanced CT scans, and tumor enhancement after venous angiography is often uneven.

　　3. Liver angiography

　　Liver angiography is very sensitive, showing rich blood supply and centripetal blood supply in tumors. A central hypoperfusion area can also be seen, indicating tumor hemorrhage. Liver biopsy should be avoided as it can cause hemorrhage.

　　4. MRI

　　Adenomas on MRI show uniform enhancement signal and clear low-density capsule on T1 images. This imaging feature can also be seen in focal nodular hyperplasia and hepatocellular carcinoma. The lesion can also appear lower in density than normal parenchyma on T1 images, making it difficult to differentiate from liver metastatic carcinoma. In cases of subacute hemorrhage, the enhanced focal area is seen on T1 and T2 images. The above examinations lack specific signs of adenoma, so the results of auxiliary examinations need to be combined with clinical findings for an accurate diagnosis.

　　5. Nuclear liver scanning

　　For nuclear liver scanning, the diameter of the tumor is greater than 2 to 3 cm, and a radioactive sparse area can be displayed within the liver.

　　Liver tumor patients should eat more protein-rich and easily digestible foods, and can drink fresh fruit and vegetable juices containing vitamins, such as milk, eggs, soy milk, lotus root starch, fruit juice, vegetable juice, minced lean meat, liver puree, etc. Vitamin C and oral iron supplements can be appropriately given to ensure timely recovery of blood loss. Pay attention not to eat food that is too cold or too hot to avoid changes in the gastric mucosal blood vessels and the occurrence of rebleeding.

　　All patients found to have space-occupying lesions in the liver and suspected to have liver adenoma should strive for early surgical treatment, regardless of whether they have symptoms. Since liver cell liver cancer can also occur in women taking oral contraceptives, it is not excluded that liver cell adenomas have the potential to become malignant. There is a certain risk in stopping oral contraceptives for patients with liver cell adenomas, and in addition, there is a risk of tumor rupture. Therefore, once diagnosed, surgical resection should be performed, and pregnant women who cannot undergo surgery should avoid pregnancy. Emergency surgery must be performed when the tumor ruptures, and the hepatic artery can be clamped first to stop bleeding. If the tumor cannot be resected due to its location at the hepatic gate or adjacent to larger blood vessels and bile ducts, the proper hepatic artery or one side of the hepatic artery should be ligated or embolized. This disease is not sensitive to radiotherapy and chemotherapy, and radiotherapy and chemotherapy have no therapeutic value. The surgical methods can be as follows:

　　1. Liver Lobectomy

　　When the tumor invades one lobe or half of the liver of the liver, local, lobar, or half-liver resection can be performed. Since most tumors have a capsule, the tumor can be resected along the capsule, and the efficacy is satisfactory. For multiple liver adenomas, the large main tumor can be resected, and the remaining small tumors can be removed one by one, and the short-term efficacy is also satisfactory.

　　2. Cyst Enucleation

　　When the adenoma is located at the first and second hepatic gates or adjacent to large blood vessels and cannot be completely resected, tumor enucleation within the cyst can be performed. The operation is relatively simple, safe, with less bleeding, and the short-term efficacy is satisfactory. However, it is difficult to distinguish this disease from low-grade malignant liver cancer with the naked eye, and it is generally advisable to strive for complete resection.

　　3. Hepatic Artery Ligation or Embolization

　　When the tumor is located at the first and second hepatic gates, deep or adjacent to large blood vessels or bile ducts, and cannot be locally resected, or when the adenoma is closely adherent to adjacent organs and difficult to separate, the left or right hepatic artery on the affected side can be ligated, or hepatic artery embolization can be performed at the same time with absorbable gelatin sponge, etc., to embolize the hepatic artery. This may play a certain role in controlling the growth of the adenoma or preventing the rupture of the adenoma.