Pathology, January 31, 2001Landry & Wilson

Dr. Oliver 10 a.m.

Tumors of the Liver

Benign Tumors

  • Cavernous Hemangioma
  • Most common tumor of the liver overall
  • Looks like reddish-purple subcapsular nodules
  • It is good that radiologists can easily detect these on CAT scans, because no treatment is required. An unnecessary needle aspiration may cause hemorrhage because the liver is so vascular.

Slide: Gross picture of a hemangioma with dark circumscribed lesions and dilated blood vessels

  • Focal Nodular Hyperplasia – probably not a true neoplasm
  • Commonly found in young to middle aged patients; more women than men
  • May be associated with oral contraceptives
  • Presents as a single large nodule where a central stellate vascularized scar contains proliferating bile ducts and inflammatory cells.

Slide: Gross picture (Robbins, pg. 886) where the central scar is apparent

Slide: Microscopic view of the tumor with a collagen stain that emphasizes the central scar.

Slide: Proliferating ducts and inflammatory cells are seen at a higher power

  • Nodular Regenerative Hyperplasia
  • A diffuse lesion with tons of nodules
  • Grossly, it looks like cirrhosis, but there is no fibrosis
  • Less common than cirrhosis
  • It is probably related to focal nodular hyperplasia.
  • Portal hypertension may develop with the nodular regenerative hyperplasia because it is diffuse, UNLIKE focal nodular hyperplasia.
  • (Gross picture in Robbins, pg. 887 and microscopic slide in Curran, pg 194)
  • Adenomas (No bile ducts – just proliferation of hepatocytes)
  • Liver Cell Adenomas (a.k.a. hepatocellular adenoma) – a benign, true neoplasm of hepatocytes
  • Usually presents in young women on oral contraceptives
  • May spontaneously regress
  • Characterized by yellow-tan nodules with sheets and cords of hepatocyte-like cells. Usually one nodule is seen with no bile ducts. This tumor is hard to differentiate from well-differentiated hepatocellular carcinoma.
  • NO PORTAL TRACTS ARE PRESENT!!
  • Caution! This tumor has a tendency to ruptureleading to intra-peritoneal hemorrhage that may be massive and life threatening. Therefore, it is usually excised.

Slide: hepatocellular adenoma with a rupture and hemorrhage (Robbins, pg 887)

Slide: High power view – See lots of hepatocytes and it almost looks normal, except there are no portal tracts. (Curran, pg 206)

  • Bile Duct Adenoma
  • Usually single, small subcapsular aggregates of uniform epithelium lined ducts

Slide: Bile duct adenoma at high power showing benign bile ducts.

Malignant Tumors of the Liver

Primary Carcinoma of the Liver (o.k. Liver cell carcinoma, hepatoma or hepatocellular carcinoma) KNOW NAMES!!

  • More common in countries endemic for viral hepatitis (especially Hepatitis B). It is especially common in China, where vertical transmission of hepatitis B frequently occurs. Nearly all of these children have chronic hepatitis, which leads to carcinoma.
  • Occurs more in older males and blacks
  • α-fetoprotein is a good tumor marker, because it is often made by these tumors.
  • Risk factors:
  • Cirrhosis (almost always precedes this carcinoma)
  • Hepatitis B (especially if vertically transmitted)
  • Hepatitis C
  • Aflatoxins
  • Anything that causes cirrhosis – i.e. alcohol
  • Hereditary tyrosinemia – a rare metabolic disease  40% develop hepatocellular carcinoma
  • Morphology
  • Unifocal, multifocal or can diffusely involve the entire liver
  • Green discolorization from bile
  • Well differentiated and bile secretion is often present (different than cholangiocarcinoma)
  • Similar to renal cell carcinoma, this cancer likes to invade and travel down veins like the portal vein or the inferior vena cava (even into the right atrium!).

Slide: Grossly, it looks like a green unifocal, large lesion. (Robbins, pg 889)

Slide: Gross picture showing a tumor and nodules with cirrhosis in the background.

Slide: Gross picture of diffuse hepatocellular carcinoma (hard to differentiate from cirrhosis or nodular hyperplasia). The tiny nodules from the cancer are hard to differentiate from cirrhosis.

Slide: Well differentiated hepatocellular carcinoma – microscopic view. Nuclei are atypical and have prominent nucleoli. Sinusoidal pattern with bile present. This is hard to differentiate from hepatocellular adenoma. Consider who the patient is – older male or young female (adenoma). Also, the plates of liver cells are usually thicker in carcinoma than in adenoma. (Curran, pg 206-207)

Slide: Malignant hepatocellular carcinoma with huge black nucleoli. It is anaplastic, so it is hard to tell if it is hepatocellular.

  • Fibrolamellar Variant of hepatocellular carcinoma
  • Young patients
  • No association with HBV or cirrhosis
  • Better prognosis

Slide: Cells of this tumor are separated by bands of fibrosis.

Cholangiocarcinoma

  • Less common cancer that arises from the bile duct.
  • Risk factors: exposure to Thorotrast (radiographic dye no longer used), liver flukes (Clonorchis)
  • NO bile secretion
  • Mucus secretion may be present
  • Has a lot of fibrosis
  • More commonly metastasize than hepatocellular carcinoma

Slide: Gross tumor looks white; it is hard and dense from fibrosis. (Robbins, pg 890)

Slide: Tumor appears to have normal ducts, except there is no bile. It is well differentiated, and some areas have more fibrosis than others. (Curran, pg 207)

Slide: Cholangiocarcinoma with a more papillary form and more fibrosis.

  • Clinical Aspects of Primary Liver Carcinoma
  • Nonspecific GI symptoms, hepatomegaly, jaundice, cirrhosis
  • Lab markers
  • Elevated serum AFP (α-fetoprotein)
  • Elevated CEA (carcinoembryonic antigen) – less specific; more likely with cholangiocarcinoma
  • Dismal prognosis  death within 6 months due to liver failure and complications from portal hypertension like esophageal variceal bleeding.
  • Rare Forms of Primary Liver Cancer
  • Hepatoblastoma
  • Fetal tumor of the liver, so it has immature hepatocytes.
  • Appears in young children and is fatal within a few years
  • Consists of fetal epithelial elements that may be admixed with foci of mesenchymal differentiation like cartilage.

Slide: Hepatoblastoma – Embryonic hepatocytes are smaller and are hard to tell that they are hepatocytes. These cells have a clear cytoplasm due to glycogen and lipid in the cytoplasm. Osteoid production is present showing the mesenchymal contribution.

  • Angiosarcoma
  • Very aggressive  fatal within 1 year
  • Occurs with exposure to vinyl chloride, arsenic, and thorotrast.

Slide: Angiosarcoma composed of endothelial cells (i.e. blood vessels) – several intertwining blood vessels with atypical nuclei

Metastatic Tumors of the Liver

  • Most common malignancy of the liver
  • Originate from breast, lung, colon, stomach
  • Presents with hepatomegaly, multiple metastatic nodules, jaundice, and abnormal liver function tests (if massive)

Slide: Gross picture with innumerable nodules throughout the liver.

Scribe note: Dr. Oliver then gave a presentation about pathology as a career. If you are interested in pathology, talk to him.

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