Benign Liver Masses

Simple and Complex Liver Cysts

Liver cysts occur in about 20% of the population. Patients often have several liver cysts scattered on both sides of the liver. Most liver cysts are small, asymptomatic, and non-cancerous. Thus, most liver cysts can be ignored. 

However, a small percentage of liver cysts are concerning and need some type of therapy. Reasons to treat liver cysts include:

Symptoms

Large liver cysts can cause abdominal bloating and pain due to stretching of the liver capsule. This pain is dull, constant, and usually located in the right upper or mid upper abdomen. Sometimes, cysts may bleed into themselves. While this bleeding is contained and almost never life threatening, it can cause acute, sharp pain. Finally, cysts can cause symptoms by pushing other organs, most often the stomach. This can result in increased pain and bloating with eating and heartburn.

Infections

Liver abscesses (most often from gut bacteria) can often appear as liver cysts on imaging. Patients with liver infections often have fevers, chills, and pain. Drainage of the infection (often by x-ray guidance) is the treatment of choice. While parasitic infectious cysts are very uncommon in the United States, immigrants from parts of the world in which these infections are endemic are at risk for these infectious cysts.      

Polycystic Liver Disease

This is a rare form of cystic liver disease in which a large portion of the liver is replaced by cystic disease. Over time, these patients may develop pain from massive liver enlargement. While liver resection may temporarily relieve pain and other symptoms, liver transplantation is the only definitive treatment.

Liver Cancer

Rarely, liver and bile duct cysts can harbor a cancerous or pre-cancerous condition. While much more common in Latin American and East Asian countries, bile duct cancers originating from liver cysts do occur in the United States. Special features noted on CT or MRI may alert physicians for these concerning liver cysts.

Therapies

• Drainage:  X-ray-guided drainage of liver cysts can be a good temporary measure, but is not definitive as the cyst will almost always come back.
  
• Marsupialization:  This is a surgical procedure that is most often performed laparoscopically (with small incisions) where the roof of the cyst is removed.  This procedure is very durable with over 95% symptom relief.
  
• Liver resection:  For infectious, cancerous, or precancerous cysts, liver resection is the treatment of choice to remove all suspicious cystic diseases.

Liver Hemangiomas

Signs & Symptoms

Hemangiomas are abnormal collections of blood vessels that can occur anywhere in the body.  They are common in the liver.   Up to 20% of the population will have at least one hemangioma in the liver.  Hemangiomas occur slightly more commonly in women compared to men.

Liver hemangiomas are benign and never turn into cancer.

Very rarely, hemangiomas can be associated with life-threatening blood disorders, may spontaneously bleed, or clot off resulting in acute pain. Based on size and location, a small percentage of liver hemangiomas can cause chronic symptoms necessitating surgery.  These symptoms include:

• Chronic pain due to stretching of the liver capsule or distension of the abdominal wall from a large hemangioma.
  
• Pain, nausea, bloating, and even weight loss from compression of the stomach, gallbladder, small intestine, or colon. 
  

Therapies

Asymptomatic hemangiomas do not require treatment.

Liver resection is the treatment of choice for symptomatic hemangiomas.  Most of these resections can be performed laparoscopically.

Rarely, radiologic procedures aimed at cutting off arterial blood supply can be used treat liver hemangiomas in patients unable to tolerate surgery.

Focal Nodular Hyperplasia (FNH) of the Liver

Signs & Symptoms

Focal nodular hyperplasia (FNH) is a liver mass comprising normal liver cells arranged abnormally because of abnormal arterial blood supply.   FNHs occur much more commonly in women compared to men.

FNHs are benign and never turn into cancer. Very rarely, FNHs may twist resulting in acute pain or spontaneously bleeding.

Based on size and location, a small percentage of FNHs can cause chronic symptoms necessitating surgery. These symptoms include:

• Chronic pain due to stretching of the liver capsule or distension of the abdominal wall from a large hemangioma.
  
• Pain, nausea, bloating, and even weight loss from compression of the stomach, gallbladder, small intestine, or colon.
  

Therapies

Asymptomatic FNHs do not require treatment.

Liver resection is the treatment of choice for FNHs.  Most of these resections can be performed laparoscopically.

Rarely, radiologic procedures aimed at cutting off arterial blood supply can be used to treat liver FNHs in patients unable to tolerate surgery.

Liver Adenomas

Signs & Symptoms

Liver adenomas are benign tumors that occur more commonly in women than in men. Oral contraceptives, other female hormone supplements, and male hormone supplements are risk factors for the presence and growth of liver adenomas. While most liver adenomas have a benign course, some adenomas are at risk for bleeding or cancer transformation.

Recently, different categories of adenomas have been discovered:

• Inflammatory adenomas (the most common) are at risk for bleeding, especially when larger than 5 cm. The risk of cancer transformation is low with this adenoma type.
  • This adenoma type occurs most commonly in patients with background fatty liver disease.
• Fatty adenomas have a very low risk of bleeding and minimal risk of cancer transformation.
• β-catenin activation mutated adenomas have a very high risk of cancer transformation.
  • These adenomas occur in both men and women.

Fortunately, the adenoma type can often be diagnosed with an MRI scan so that a liver biopsy is not needed in most cases.

Therapies

Appropriate management of liver adenomas is complex and should be done by a liver specialist.

• Any adenoma found in a male should be surgically removed, when possible, because of the risk of cancer transformation.
• Any adenoma with a prior history of bleeding should be removed, when possible, to prevent further bleeding.
• Any adenoma that has signs of cancer transformation on imaging should be removed, when possible.
• Inflammatory adenomas greater than 5 cm or are growing and do not shrink after stopping all female hormone therapy should be removed.
• Other adenomas may be observed with imaging.