Mass (Focal Liver) Evaluation



Mass (Focal Liver) Evaluation





DEFINITION:



  • Benign or Malignant, Primary (originating in the liver) or Secondary (metastases), lesions of the liver


EPIDEMIOLOGY:



  • See Etiologies below for specific conditions


ETIOLOGIES:



  • Differential Diagnosis

    Benign

    Malignant


    Benign


    Epithelial

    Hepatic adenoma

    Hepatocellular carcinoma

    Other:

    Focal nodular hyperplasia (FNH)

    Bile duct adenoma

    Cholangiocarcinoma


    Liver abscess

    Biliary cystadenoma

    Biliary cystadenocarcinoma


    Regenerative nodule(s) of cirrhosis

    —

    Squamous carcinoma


    Focal fatty infiltration
    Simple hepatic cysts


    Mesenchymal

    Cavernous Hemangioma

    Angiosarcoma

    Fibroma, Lipoma

    Fibrosarcoma, Liposarcoma

    Leiomyoma

    Leiomyosarcoma


    Malignant

    —

    Primary hepatic lymphoma

    Other:

    Metastatic tumors


    Modified from Kew MC: Tumors of the liver. In Zakim D, Boyer TD (eds): Hepatology: A Textbook of Liver Disease, 3rd ed. Philadelphia, W.B. Saunders, 1996, pp 1513.



  • Cavernous hemangiomas: most common benign cause, more common in ♀ as solitary (60%) or multiple asymptomatic masses



    • Most <3 cm, right lobe; Microscopically consist of blood-filled vascular sinusoids separated by connective tissue septae


    • Seldom estrogen sensitive, rarely cause symptoms and do not pose a threat for rupture or malignant degeneration; No therapy


  • Focal nodular hyperplasia (FNH): second most common benign lesion, over 90% occur in ♀, between 20-60 years



    • Round, nonencapsulated mass, usually with vascular central scar with fibrous septae radiating out, including Kupffer cells


    • Theorized to result from hyperplastic tissue response to a congenital arterial malformation


    • CT/MRI show “spoke wheel” in arterial phase, T2 demonstrates hyperintense (opposite of Fibrolammelar hepatocellular cancer)



      • Confirm with technetium-sulfur (nuclear medicine) scan: exploits the Kupffer cells as they uptake sulfur


    • Often associated with hemangiomas (22%) or very rarely Fibrolamellar HCC


    • Does not pose a threat for rupture or malignant degeneration; Difficult question is distinguishing from Adenoma



      • FNH: central scar on CT/MRI, ↑ uptake on Tc 99 m sulfur colloid scintigraphy, biopsy shows bile ducts in fibrous septa


    • Resection usually not necessary



  • Hepatic Adenomas: Women and related to OCP use, benign tumor but often symptomatic, 4 per 100,000 ♀ (anabolic steroids in males is a risk factor)



    • Microscopically they are monotonous sheets of normal or small hepatocytes with no bile ducts, portal tracts, or central veins


    • CT demonstrates enhancement without central scar during arterial phase


    • Surgical resection recommended (even with stopping OCP): spontaneous rupture/hemorrhage up to 30%, ? HCC risk


    • Hepatic Adenomatosis (>10 adenomas) is extremely rare and considered a distinct entity from Hepatic Adenoma


  • Liver Cysts: prevalence in general population 3-4% and increase with age; more common in ♀



    • Usually asymptomatic and frequency occur with other liver lesions/masses


    • Characterized by thin-walled structures lined with cuboidal bile duct epithelium and filled with isotonic fluid (lucent on U/S)


  • Fatty infiltration: occurs with obesity, diabetes, ETOH intake, chemotherapy (especially with altered nutrition status)



    • Can be focal in nature producing appearance of a mass on imaging


  • Metastatic liver disease more common than primary hepatic tumors; Cancers: colon, stomach, pancreas, breast, lung, esophageal, renal



    • Multiple liver defects suggest metastases, only 2% are single lesions; Involvement of both lobes is common, but 20% right lobe only


  • Hepatocellular carcinoma (HCC) is by far most common malignancy originating in liver; accounts for 80% of primary liver cancers

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Aug 24, 2016 | Posted by in GASTROENTEROLOGY | Comments Off on Mass (Focal Liver) Evaluation

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