Histopathological Characteristics according to the 2019 WHO Classification and VETC Pattern in Hepatocellular Carcinoma: A Retrospective Study in Viet Nam

Background: The histopathological heterogeneity of hepatocellular carcinoma (HCC) significantly influences patient management and prognosis. However, data on HCC subtypes classified by the 2019 World Health Organization (WHO) criteria and on the vessels-encapsulating tumor cluster (VETC) pattern—a recently described vascular architecture—remain scarce. This study aimed to delineate the histopathological subtypes of HCC according to the 2019 WHO classification, evaluate the prevalence of the VETC pattern, and investigate their clinicopathological associations. Methods: A retrospective, cross-sectional study was performed on 150 patients who underwent curative-intent hepatectomy for HCC at Bach Mai Hospital between 2019 and 2021. Results: The mean age was 56.3 ± 10.8 years, and the male-to-female ratio was 5.5:1. Chronic hepatitis B or C infection was present in 86 % of patients. Special histological subtypes—macrotrabecular and steatohepatitic (10.7 % each), scirrhous (8.7 %), clear cell (4.7 %), lymphocyte-rich (2.7 %), neutrophil-rich (0.7 %), and chromophobe (0.7 %)—were identified in 38.7 % of tumors. The microtrabecular architecture predominated (74 %), whereas glandular and macrotrabecular patterns were less frequent. The macrotrabecular pattern was significantly associated with elevated serum alpha-fetoprotein (AFP) levels and histological vascular invasion (p < 0.05). Similarly, the macrotrabecular and scirrhous subtypes correlated with high AFP levels and vascular invasion (p < 0.05). No significant association was found between histological subtypes and tumor stage. The VETC pattern was observed in 24 % of cases and was linked to vascular invasion (p < 0.05). Conclusion: This study underscores the broad spectrum of HCC subtypes and architectural patterns in Vietnamese patients and highlights the clinical relevance of the VETC phenotype. These insights may facilitate more refined prognostication and individualized therapeutic strategies.