MALIGNANT TUMOURS (Robbins pp 888 / 899)

Primary:

• Epidemiology: Blacks have 4 fold increased risk, males > females 8:1, distribution influenced by prevalence of HBV infection. In western nations, HCV + alcohol are common associations.

Hepatocellular carcinoma:

• Pathogenesis: HBV, HCV cause inflammation ≫ cell death. New hepatocytes form. Repeated such cycles will induce genetic mutations ≫ transforming into neoplasia. Aflatoxins are most important environment factor for hepatocellular carcinoma. Aflatoxins are activated in hepatocytes ≫ products embed into DNA ≫ genetic mutations occur. Cirrhosis is another risk factor.
  
• Morphology: The tumour can be a massive unifocal lesion, multifocal – nodules distributed over greater area, diffusely infiltrative – involves entire liver. The nodules are paler in colour than normal hepatic tissue, and they are soft. Histologically, the cells can range from well differentiated ≫ anaplastic. They can be arranged in trabeculae or in an acinar pattern. Tumour mass can extend into the portal veins ≫ metastases.
• Clinical features: abdominal pain, malaise, weight loss, palpable mass. Elevated serum alpha-fetoprotein in 60-75% of cases. False positives occur in many other conditions. Perform ultrasound, hepatic angiography, CT, MRI.

Cholangiocarcinoma (Intra-hepatic biliary tract carcinomas):

• This is glandular proliferation of the epithelium of bile ducts within the liver. There is increased risk in patients exposed to Thorotrast (radiological contrast medium used previously), & liver flukes (Chlonorchis sinensis), & ulcerative colitis patients.
  
• Morphology: This is an adenocarcinoma of the bile duct epithelium. You see lots of tubular glands lined with cuboidal cells, and the glands are separated by dense collagenous tissue.
  
• Clinical features: Usually not detected until very late, prognosis is bad ≫ death within 6 months.

Angiosarcomas:

• This is a highly malignant endothelial neoplasm (prognosis poor ≫ 5 year survival). Hepatic angiosarcomas are rare, but have direct risk factors which are: arsenic, Thorotrast, polyvinyl chloride.

Secondary (Robbins pp 891)

Liver metastases is more common than primary cancer developing there. The most common areas from which metastases arrive are: breast, colon & lung. Multiple nodules of metastatic tissue is present ≫ hepatomegaly (palpable nodularity). Some nodules have central area of necrosis, as they rapidly outgrow their blood supply (macroscopy).

Category: Pathology Notes