The liver is the engine of the human body. It is basically composed of 2 types of cells (a cell is the basic building block of the human body) – hepatocytes (liver cells) and cholangiocytes (bile duct cells). It also has other supporting tissue and their respective cells. The hepatocytes are by far the most numerous cell type, not surprisingly tumours (otherwise called mass or lump. “Tumor” means lump in Latin), of this cell form the majority of abnormal growths in the liver. Abnormal growths can be benign (that is, they do not grow rapidly, spread to other parts of the organ or to other parts of the body) or malignant (grow rapidly, spread to other parts of the organ and to other parts of the body, i.e. cancer). These abnormal growths from liver cells are Focal nodular hyperplasia (FNH), Adenomas (the benign variety) and hepatocellular cancer (otherwise called Hepatoma/HCC, the cancerous type). What we need to recognize is that certain adenomas can turn into HCC, over a period of time. The other type of growths in the liver are those that have originated elsewhere in the body and spread to the liver, for example a growth of the breast spreading to the liver. These are in fact the commonest tumours of the liver. I will discuss these at a later date.
Benign growths of the liver
Common benign growths are Haemangiomas, FNH and Adenoma. Most of these are identified when a scan is performed as investigation for some other problem. Accurate diagnosis of the nature of these lumps is important to determine the type of treatment needed. This can be ascertained by a carefully selected scan like an Ultrasound, CT scan or an MRI. The technology of these scans is continuing to evolve and get better year on year. There are different types of Ultrasound, CT and MRI scans with different applications, based on whether contrast is used or not, the different phases of scanning, the type of MRI scanning sequence etc. Therefore, these scans although commonly available and used very frequently, need to be performed under the supervision of a team involving Liver doctors and radiologist who is well versed in the diagnosis of liver lumps, for accurate diagnosis without the need for unnecessary tests (Box 1).
Haemangiomas are by far the commonest. It is estimated that 5% of the adult population harbor this lump in their livers! They occur in both sexes and at all ages but are commonest between 30 to 50 years in women. Most of them are small, less than 4-5 cms in diameter and are are identified on Ultrasound. MRI and its various applications is the scan of choice for accurate diagnosis. This is crucial as most of them do not need treatment.
Focal Nodular Hyperplasia (FNH) are the second most common liver lumps. They are usually single and small (less than 4 cms) and occur in women between 35 – 50 years of age. About 2.5-3% of population harbor this lump in their livers. Special MRI techniques using special contrast agents is diagnostic and the findings are quite distinct from haemangiomas. Again treatment is not recommended apart from selected circumstances. Assessment in a dedicated Liver team is recommended for accurate diagnosis and a proper management plan to be formulated.
Hepatic adenomas (Hepatocellular adenoma, HCA) are rare lumps and occur in 0.2 to 0.3% of the population, again occurring mostly in young women during their reproductive period. They are again solitary and most usually 3-4 ms in diameter.
There are a couple characteristics which make this lump different from the previous 2, there is a strong relation between hormones the development of HCA and some of these HCA can turn into the malignant Hepatocellular carcinoma (HCC). Therefore, accurate characterization and diagnosis of these HCA is essential. Sometimes biopsy of the lump, molecular and genetic tests maybe necessary to determine if the HCA has a high chance of progressing to HCC. Imaging tests are generally adequate, contrast MRI Liver and its different techniques is accurate in diagnosing HCA and sub-typing it, however CT and contrast-enhanced Ultrasound is sometimes necessary along with MRI.
Generally, a HCA in a male is recommended for surgical resection. While in women, discontinuation of the OCP pill/ any other such hormone is recommended for a period of 6 months, if the HCA does not have any worrying features and size is less than 5 cms. IF HCA is larger than 5 cms and has features suggestive of a high risk for change to HCC, surgery is advised. Again these decisions have to be made as a part of a Multi-disciplinary team (Box 1)
Malignant growths beginning within the Liver
As mentioned earlier, usually malignant growths which are seen in the liver spread to it from elsewhere in the body. Hepatocellular cancer/Hepatoma (HCC) is the commonest malignant tumour beginning within the liver, as apposed to those that spread to the liver from elsewhere. It occurs between 40-70 years of age and occurs commonly in men. It is estimated that 17000 new patients develop this tumour every year in India. The vast majority (> 80%) of these develop in patients who have chronic liver disease (cirrhosis). Importantly the number of HCC cases is increasing year on year as cirrhosis due to fatty liver disease, Hepatitis B (3% of Indian population carry this virus, ie nearly 40 million individuals) and alcohol are continuing to increase in India. Nearly overall it is the 4th or 5th most common cause of cancer and the second most common cause of cancer-related death. This is continuing to increase too. We do not have a national policy in India to screen and diagnose these lumps in the liver at an early stage. Most patients present at a late stage when effective treatment is not possible.
Hepatitis B is a vaccine-preventable disease, there are good drugs to treat it and decrease the risk of cirrhosis and HCC in HBV patients, therefore it is important to test for this virus infection. The fatty liver disease can cause chronic liver damage and HCC, regular exercise and consuming a balanced diet can reduce the risk of fatty liver disease.
The usual mode of detection of these growths is when a scan is done for some other reason. Occasionally patients can develop pain in the abdomen or jaundice which leads to an investigation. The treatment of HCC depends on the extent of tumour, the extent of the chronic liver disease (the stage of cirrhosis) and the overall condition of the patient. These patients are best seen, assessed and treated in a team (Box 1) which specializes in the treatment of Liver disease.
The best treatment for HCC is surgery. However, this is suitable only for certain carefully selected patients. This can take the form of liver resection (where a portion of the liver with tumour is removed) or liver transplantation (where the whole liver is removed and a donated liver (full or partial) is replaced into the patient. Indeed surgical has excellent survival rates; more than 75% of patients survive for more than 5 years after resection or transplantation making treatment for these cancers one of the most satisfactory.
Other treatments which can be combined with surgery in selected patients or can be combined with patients not suitable for surgery are different types of Interventional radiological therapy – chemotherapy or radiotherapy delivered through fine catheters introduced into the blood vessels of the liver (TACE: Transarterial chemotherapy, TARE: Transarterial radiotherapy) and or heat energy delivered to the tumour area by means of carefully placed needles/probes (RFA: radiofrequency ablation, MWA: microwave ablation).
HCC is unique cancer as its treatment should be tailored to the patient, the treatments are varied and range from catheter-based non-invasive treatment to major surgery and transplantation. This necessitates that HCC patients are best managed in a multidisciplinary team which is highly skilled in and specializes in the management of liver diseases.
Box 1: A liver tumour multidisciplinary team – Integrated Liver Care team
The team should be one with expertise in the management of benign liver lesions and should include a Hepatologist, a Hepatobiliary & Transplant surgeon, Diagnostic and Interventional radiologists, Medical oncologist and a Pathologist.
Each member of the team must hold specific and relevant training, expertise and experience relevant to the management of benign liver lesions.
The team should be one with the skills required not only to appropriately manage these patients but also to manage the rare but known complications of diagnostic or therapeutic interventions.
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