Liver Cysts and Tumours

LIVER CYSTS AND TUMOURS

The liver is made up of cells called hepatocytes. There are several other specialized cells in the liver. Besides these cells, bile ducts and blood vessels criss-cross across the liver. These structures are made up of several types of cells. Any of these cells can become diseased, resulting in the formation of a tumour, cancer, or cyst.

A tumour is formed when a normal cell gets the capacity to continuously divide and grow. This results in the formation of a mass. It could be cancerous (malignant) or non-cancerous (benign). A cancerous tumour will spread and non-cancerous will not. Besides these tumours, several types of cysts can also form in the liver. A cyst is a fluid-filled structure surrounded by a wall or membrane. Several types of cysts occur in the liver. These include simple cyst, polycystic liver disease, hydatid cyst, liver abscesses, cystadenoma of the liver, various cystic tumours and Caroli’s disease.

Benign liver tumours are more frequent than liver cancers. They usually remain benign and rarely turn cancerous. Most do not cause any symptoms. They are commonly detected when an imaging test (ultrasound, CT or MRI) is done for evaluation of a symptom of some other disease. When a lesion is detected like this (incidentally), it is called an “incidentaloma”. The widespread use of imaging modalities has resulted in an increasing number of these lesions being diagnosed. Sometimes they cause symptoms, can have complications, or can turn cancerous.

Some common benign liver tumours include hemangioma, focal nodular hyperplasia and hepatocellular adenoma.

Hemangioma: It is a tumour of blood vessels and most common benign liver tumour. It is a mass of abnormal blood vessels. It is a common tumour and occurs in 1-5% of adults. There can be many hemangiomas in 10% of cases. Hemangiomas over 5 cm are called giant hemangiomas. Hemangiomas are usually asymptomatic. They can cause symptoms when large. Their diagnosis is confirmed on contrast-enhanced CT and/or MRI. complications such as rupture can sometimes occur with these tumours. Some atypical hemangiomas can be difficult to differentiate from other liver tumours. Surgical resection of hemangioma is required if it is causing symptoms, when it is large and at risk of rupture or when it is rapidly enlarging.

Focal nodular hyperplasia

Focal nodular hyperplasia is the second most common form of benign liver tumour after hemangiomas. It contains a scar in the centre. It occurs more commonly in women from their second to the fourth decade. It can be multifocal in 10-20%. It never becomes cancerous and usually does not increase in size. Spontaneous rupture and bleeding also do not occur. They can occasionally cause symptoms.

Hepatocellular Adenoma

It is a tumour of hepatocytes. It occurs primarily in young women. Intake of oral contraceptive pills and pregnancy is a risk factor for the occurrence of this tumour. Those that are related to oral contraceptive use will usually regress after stopping it. It can occasionally become cancerous. These tumours may rupture and bleed into the abdominal cavity. Surgical resection is required when it is on the surface of the liver and at risk of rupture and when the size is more than 5 cm. Certain subtypes are more at risk of cancerous transformation and should be resected.

Other less common benign liver tumours: Angiomyolipoma, Hepatic lipoma, Mesenchymal hamartoma, Benign biliary hamartoma (bile duct adenoma, biliary adenofibroma and Von Meyenberg complex)

Symptoms

Majority of these patients do not have any symptoms and the lesion is detected on an imaging test done for unrelated reasons. Symptoms when present can include:

• Abdominal pain
• Abdominal discomfort
• Feeling of fullness
• Nausea or vomiting
• Loss of appetite
• Early satiety

Diagnosis

Blood tests: Complete blood count measures the distinct cells in the blood. Liver and kidney function tests assess the function of these organs. A liver function test is usually normal. Blood clotting tests will show whether the liver is making enough of them. The blood test will also check for hepatitis B and C.

Tumour markers: A blood test will also look for tumour markers. Tumour markers are elevated in malignant tumours and help differentiate benign tumours from malignant.

Ultrasound: It is a basic investigation to look inside your abdomen and usually the first investigation which detects the mass in the liver. It uses sound waves which bounce off the internal organs and creates a picture of them on the computer monitor.

Computed tomography scan (CT scan): For liver lesions, triple-phase CT helps us determine the type of lesion. In this, the images are enhanced with contrast by injecting it into the blood circulation and scanning is done in phases while the contrast passes through the liver. The CT scan gives information about the size and location of tumours in the liver. It also shows the relation of cancer to bile duct and blood vessels in the liver.

Magnetic resonance imaging (MRI): It is a test like a CT scan. Instead of X-Ray, strong magnetic fields and radio waves are used to take images. MRI is a useful modality to distinguish types of liver tumours. MR images are also enhanced with liver-specific contrast agents, acquiring images in phases.

Biopsy: Biopsy means sampling a small piece of the tumour and examining it under a microscope. A biopsy is not always needed for the diagnosis of liver lesion, only when the diagnosis is uncertain based on imaging studies.

TREATMENT

Treatment of these lesions depends on symptoms, type of tumour, size, and complications. Surgical resection is indicated in patients with complication and symptoms. Surgical removal is also done in patients where the likelihood of complications or cancerous transformation is high. Some patients would require surgery because the workup will fail to distinguish benign from malignant tumours.

Surgery for liver tumour involves the removal of the tumour-bearing part of the liver.

HEPATECTOMY OR LIVER RESECTION

Hepatectomy is the removal of part of the liver containing cancer with healthy margins. It is done when the remaining liver after surgery is of adequate size and functioning well. The remaining liver grows over a few weeks. With advancements in surgical technique, we do this procedure laparoscopically in selected patients.

LAPAROSCOPIC LIVER RESECTION

Open surgery uses a long incision over the abdomen for the surgery. The laparoscopic approach uses minimally invasive techniques to do the same surgery with tiny incisions. This entails the insertion of special long thin surgical tools through these small holes. Laparoscopic liver resection results in faster recovery and reduced pain compared to conventional open surgery.