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Chapters
0:00 Introduction
0:32 Types of Liver Lesions
1:33 Causes of Liver Lesions
2:06 Symptoms of Liver Lesions
2:28 Diagnosis of Liver Lesions
2:49 Treatment of Liver Lesions
3:19 Prevention of Liver Lesions
Liver tumors (also known as hepatic 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.[1] Liver tumors can be classified as benign (non-cancerous) or malignant (cancerous) growths. They may be discovered on medical imaging (even for a different reason than the cancer itself), and the diagnosis is often confirmed with liver biopsy.[2] 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.[3]
Benign
There are several types of benign liver tumors. They are caused by either abnormal growth of neoplastic cells or in response to liver injury, known as regenerative nodules.[2] One way to categorize benign liver tumors is by their anatomic source, such as hepatocellular, biliary, or stromal.[2]: 693-704 
Hemangiomas
Cavernous hemangiomas (also called hepatic hemangioma or liver hemangioma) are the most common type of benign liver tumor, found in 3%-10% of people.[2] They are made up of blood clusters that are surrounded by endothelial cells.[5] These hemangiomas get their blood supply from the hepatic artery and its branches.[5] These tumors are most common in women.[5] The cause of liver hemangiomas remains unknown; however, it may have congenital and genetic components.[5] They are not known to become malignant based on the available existing literature.[5]
Liver hemangiomas do not usually cause symptoms.[2][5] They are usually small, with sizes up to 10 centimeters.[5] Their size tends to remain stable overtime.[5] However, if the hemangioma is large it can cause abdominal pain, a sense of fullness in right upper abdominal area, heart problems, and coagulation dysfunction.[2][5] Cavernous hemangiomas are diagnosed with medical imaging (do not usually need biopsy to confirm diagnosis).[2]
Given their benign course and often asymptomatic nature, cavernous hemangiomas are typically diagnosed incidentally (e.g. when medical imaging is obtained for another reason).[5] In terms of management, they are usually monitored with periodic imaging as well as more closely if the person becomes pregnant.[5] If the cavernous hemangioma grows quickly or the patient is symptomatic, further medical intervention is warranted.[5] Therapies include open or laparoscopic surgical resection, arterial embolization, or radio-frequency ablation.[5] In terms of complications of hepatic hemangiomas, it is very rare for a hepatic hemangioma to rupture or bleed.[6]