Imaging studies of the liver, including ultrasound, CT and MRI scans, allow doctors to visualize the structure and texture of the organ. The liver normally has a uniform appearance on imaging scans. A spot on the liver describes an area that appears different from the majority of the liver tissue. Infections, inflammatory reactions and various types of noncancerous and cancerous tumors can appear as spots on the liver. Additional tests help identify the underlying cause of a spot seen on a liver imaging study.
A hemangioma is a noncancerous tumor composed of abnormal blood vessels that form during development in the womb. Hemangiomas are the most common type of noncancerous liver tumor, reports the online medical encyclopedia MedlinePlus. The tumors occur more commonly in females than in males and may present at any age. Most hemangiomas do not cause symptoms and are discovered incidentally. Rarely, blood vessels within a hemangioma rupture, necessitating treatment to stop the bleeding.
A liver adenoma is an uncommon noncancerous liver tumor. Women taking oral contraceptives are most frequently affected. Liver adenomas, also known as hepatocellular adenomas, arise from the abnormal growth of liver cells, or hepatocytes. In rare cases, multiple liver adenomas develop in association with an inherited abnormality known as familial liver adenomatosis, notes the Atlas of Genetics and Cytogenetics in Oncology and Haematology. Among women taking oral contraceptives, discontinuation of the drugs generally leads to resolution of the tumor. Large liver adenomas may require surgical removal.
Liver granulomas represent distinct masses of inflammatory tissue that appear as spots on liver images. Granulomas may form in response to infections that involve the liver, such as tuberculosis, schistosomiasis, cat scratch fever, syphilis, histoplasmosis, toxoplasmosis, tularemia and cryptococcosis, reports The Merck Manual for Healthcare Professionals. Other conditions that may cause liver granulomas include sarcoidosis, Hodgkin lymphoma and polymyalgia rheumatica, an autoimmune disorder. Most liver granulomas do not cause liver-related symptoms. Treatment addresses the underlying condition causing the liver granulomas.
Liver cancer is the most serious and potentially life-threatening cause of spots on a liver scan. The American Cancer Society estimates the occurrence of more than 24,000 new cases of liver cancer among Americans in 2010. Risk factors for liver cancer include chronic viral hepatitis, liver cirrhosis, alcohol abuse and iron overload, according to the National Cancer Institute. Liver cancer generally does not cause symptoms until the disease reaches an advanced stage. Regular ultrasound monitoring of the liver among people at high risk for liver cancer can help detect early-stage disease.
Metastatic Liver Cancer
Certain types of cancer commonly spread to the liver, including lung, breast, colon and pancreatic cancers. The term metastatic liver cancer, or liver "mets," describes liver tumors arising from the spread of cancer from another location. Metastatic liver cancer proves more common than cancer arising from the liver itself, notes The Merck Manual for Healthcare Professionals. Metastatic liver cancer is an ominous development because cancer that spreads from one organ to another often cannot be cured.