| Hepatocellular adenoma | |
|---|---|
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| Micrograph of a hepatic adenoma (bottom of image). H&E stain | |
| Specialty | Gastroenterology, oncology  |
Hepatocellular adenoma (also known as hepatic adenoma or hepadenoma) is a rare, benign liver tumor. It most commonly occurs in people with elevated systemic levels of estrogen, classically in women taking estrogen-containing oral contraceptive medication. [1]
About 25–50% of hepatic adenomas cause pain in the right upper quadrant or epigastric region of the abdomen. [2] Since hepatic adenomas can be large (8–15 cm), patients may notice a palpable mass. However, hepatic adenomas are usually asymptomatic, and may be discovered incidentally on imaging ordered for some unrelated reason. [2] Large hepatic adenomas have a tendency to rupture and bleed massively inside the abdomen. If not treated, there is a 30% risk of bleeding. [3] Bleeding may lead to hypotension, tachycardia, and sweating (diaphoresis).[ citation needed ]
Hepatic adenomas are associated with glycogen storage diseases, type 1 diabetes, as well as anabolic steroid use.
Hepatic adenoma is usually detected by imaging, typically an ultrasound or CT, as a hyperenhancing liver nodule. Given that several liver tumors appear similarly on these imaging modalities, a multi-phase contrast-enhanced imaging study such as CT or MRI may be used to provide more information. [3] [4] The significance of making a specific diagnosis is that, unlike other benign liver tumors such as hemangioma and focal nodular hyperplasia, hepatic adenomas have a small but meaningful risk of progressing into a malignancy. [3] Although imaging provides supportive information, a definitive diagnosis of hepatic adenoma requires biopsy of the tissue.[ citation needed ]
Hepatic adenomas may be sub-classified according to morphologic appearance by microscopy, immunohistochemical staining, and genetic mutational analysis: [5] [6] [7]
Although the significance of this categorization is still under research, the subtypes may indicate differential risk of hemorrhage or malignant transformation.[ citation needed ]
Hepatic adenomas are, typically, well-circumscribed nodules that consist of sheets of hepatocytes with a bubbly vacuolated cytoplasm. The hepatocytes are on a regular reticulin scaffold and less or equal to three cell thick.
The histologic diagnosis of hepatic adenomas can be aided by reticulin staining. In hepatic adenomas, the reticulin scaffold is preserved and hepatocytes do not form layers of four or more hepatocytes, as is seen in hepatocellular carcinoma.
Cells resemble normal hepatocytes and are traversed by blood vessels but lack portal tracts or central veins.
Some authors feel that all hepatocellular adenoma should be resected, because of the risk of rupture causing bleeding and because they may contain malignant cells. [8] Current recommendations are that all hepatic adenomas should be resected, as long as they are surgically accessible and the patient is a reasonable operative candidate. [9] Patients with adenomas should avoid oral contraceptives or hormonal replacement therapy.[ citation needed ]
Pregnancy could cause the adenoma to grow faster, so patients with hepatic adenomas should avoid pregnancy. [10]
The majority of hepatic adenomas arise in women aged 20–40, most of whom use oral contraceptives. Other medications which also alter circulating hormone levels, such as anabolic or androgenic steroids, Barbiturates, clomifene, have also been implicated as risk factors. [2]
Incidence of adenomas may be increased in metabolic diseases, including tyrosinemia and type 1 diabetes mellitus, and glycogen storage diseases (types 1 and 3), as well as in beta-thalassemia and hemochromatosis. [2]
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide.
Liver tumors are abnormal growth of liver cells on or in the liver. Several distinct types of tumors can develop in the liver because the liver is made up of various cell types. Liver tumors can be classified as benign (non-cancerous) or malignant (cancerous) growths. They may be discovered on medical imaging, and the diagnosis is often confirmed with liver biopsy. Signs and symptoms of liver masses vary from being asymptomatic to patients presenting with an abdominal mass, hepatomegaly, abdominal pain, jaundice, or some other liver dysfunction. Treatment varies and is highly specific to the type of liver tumor.
An adenoma is a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organs, including the adrenal glands, pituitary gland, thyroid, prostate, and others. Some adenomas grow from epithelial tissue in nonglandular areas but express glandular tissue structure. Although adenomas are benign, they should be treated as pre-cancerous. Over time adenomas may transform to become malignant, at which point they are called adenocarcinomas. Most adenomas do not transform. However, even though benign, they have the potential to cause serious health complications by compressing other structures and by producing large amounts of hormones in an unregulated, non-feedback-dependent manner. Some adenomas are too small to be seen macroscopically but can still cause clinical symptoms.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajal, or similar cells. They are defined as tumors whose behavior is driven by mutations in the KIT gene (85%), PDGFRA gene (10%), or BRAF kinase (rare). 95% of GISTs stain positively for KIT (CD117). Most (66%) occur in the stomach and gastric GISTs have a lower malignant potential than tumors found elsewhere in the GI tract.
A Klatskin tumor is a cholangiocarcinoma occurring at the confluence of the right and left hepatic bile ducts. The disease was named after Gerald Klatskin, who in 1965 described 15 cases and found some characteristics for this type of cholangiocarcinoma
Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common.
A benign tumor is a mass of cells (tumor) that does not invade neighboring tissue or metastasize. Compared to malignant (cancerous) tumors, benign tumors generally have a slower growth rate. Benign tumors have relatively well differentiated cells. They are often surrounded by an outer surface or stay contained within the epithelium. Common examples of benign tumors include moles and uterine fibroids.
Glycogen storage disease type I is an inherited disease that prevents the liver from properly breaking down stored glycogen, which is necessary to maintain adequate blood sugar levels. GSD I is divided into two main types, GSD Ia and GSD Ib, which differ in cause, presentation, and treatment. There are also possibly rarer subtypes, the translocases for inorganic phosphate or glucose ; however, a recent study suggests that the biochemical assays used to differentiate GSD Ic and GSD Id from GSD Ib are not reliable, and are therefore GSD Ib.
Transcatheter arterial chemoembolization (TACE) is a minimally invasive procedure performed in interventional radiology to restrict a tumor's blood supply. Small embolic particles coated with chemotherapeutic drugs are injected selectively through a catheter into an artery directly supplying the tumor. These particles both block the blood supply and induce cytotoxicity, attacking the tumor in several ways.
Liver biopsy is the biopsy from the liver. It is a medical test that is done to aid diagnosis of liver disease, to assess the severity of known liver disease, and to monitor the progress of treatment.
Hepatectomy is the surgical resection of the liver. While the term is often employed for the removal of the liver from a liver transplant donor, this article will focus on partial resections of hepatic tissue and hepatoportoenterostomy.
Focal nodular hyperplasia is a benign tumor of the liver, which is the second most prevalent tumor of the liver after hepatic hemangioma. It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour was once often resected because it was difficult to distinguish from hepatic adenoma, but with modern multiphase imaging it is usually now diagnosed by strict imaging criteria and not resected.
Liver cancer is cancer that starts in the liver. Liver cancer can be primary or secondary. Liver metastasis is more common than that which starts in the liver. Liver cancer is increasing globally.
A colorectal polyp is a polyp occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer.
HNF1 homeobox A, also known as HNF1A, is a human gene on chromosome 12. It is ubiquitously expressed in many tissues and cell types. The protein encoded by this gene is a transcription factor that is highly expressed in the liver and is involved in the regulation of the expression of several liver-specific genes. Mutations in the HNF1A gene have been known to cause diabetes. The HNF1A gene also contains a SNP associated with increased risk of coronary artery disease.
Computed tomography of the abdomen and pelvis is an application of computed tomography (CT) and is a sensitive method for diagnosis of abdominal diseases. It is used frequently to determine stage of cancer and to follow progress. It is also a useful test to investigate acute abdominal pain. Renal stones, appendicitis, pancreatitis, diverticulitis, abdominal aortic aneurysm, and bowel obstruction are conditions that are readily diagnosed and assessed with CT. CT is also the first line for detecting solid organ injury after trauma.
The colorectal adenoma is a benign glandular tumor of the colon and the rectum. It is a precursor lesion of the colorectal adenocarcinoma. They often manifest as colorectal polyps.
A cavernous liver hemangioma or hepatic hemangioma is a benign tumor of the liver composed of hepatic endothelial cells. It is the most common benign liver tumour, and is usually asymptomatic and diagnosed incidentally on radiological imaging. Liver hemangiomas are thought to be congenital in origin. Several subtypes exist, including the giant hepatic haemangioma, which can cause significant complications.
Ultrasonography of liver tumors involves two stages: detection and characterization.
