Intratumoral sampling variability in hepatocellular carcinoma: a case report

Area of Science:

• Hepatology
• Oncology
• Pathology

Background:

• Differentiating hepatocellular carcinoma (HCC) from benign liver lesions is crucial but histologically challenging, especially with liver biopsies.
• Immunohistochemistry aids histological typing, with CK18, Hep Par 1, and glypican 3 (GPC3) being key markers for HCC diagnosis.

Observation:

• A case of HCC in a 72-year-old male with HBV-related chronic liver disease presented significant intratumoral morphological and immunohistochemical variability.
• Tumor areas ranged from well-differentiated, resembling regenerative nodules, to undifferentiated with atypical multinucleated cells.
• Hep Par 1 showed near-universal staining, while glypican 3 and CK18 exhibited patchy immunoreactivity, with negative regions adjacent to positive ones.

Findings:

• Intratumoral heterogeneity in HCC can mimic benign nodules and affect immunohistochemical marker interpretation.
• Hep Par 1, glypican 3, and CK18 expression can be variable within a single HCC tumor.
• Sampling variability in small liver core biopsies can lead to diagnostic challenges and affect tumor grading.

Implications:

• Accurate HCC diagnosis requires careful consideration of intratumoral variability and potential sampling bias in liver biopsies.
• Immunohistochemical results for Hep Par 1, glypican 3, and CK18 should be interpreted cautiously in the context of morphological heterogeneity.
• The findings underscore the importance of comprehensive sampling and interpretation in diagnosing and grading HCC, particularly in challenging biopsy cases.