Hepatocellular carcinoma: Morphological spectrum and subtyping as per the World Health Organization classification on FNA biopsy with cell block samples

Abstract

Background

Hepatocellular carcinoma (HCC) may be diagnosed and further subclassified in surgical specimen as per the recent World Health Organization (WHO) classification into several distinct subtypes with prognostic implications. The aim of this study was to apply this WHO classification on fine-needle aspiration biopsy (FNAB) samples of HCC and describe their features.

Methods

This was a retrospective analysis of all ultrasound-guided FNAB of liver mass lesions in patients with suspected HCC (n = 164) over a 7-year period. Detailed morphological assessment of cytopathological features and grading was done and correlated with each other. HCC was subtyped further in cases with available cell blocks (n = 126).

Results

A total of 164 cases of HCC were evaluated on FNAB with age range of 18–88 years (mean, 60 years), and with 140 (85.4%) male and 24 (14.6%) female patients. Grading performed on 160 cases of HCC (after excluding fibrolamellar HCC) revealed 23 well differentiated, 127 moderately differentiated, and 10 poorly differentiated HCCs. Subtyping was feasible in 126 cases, of which 26 cases (20.6%) showed specific subtypes that were steatohepatitic (8), lymphocyte-rich (8), fibrolamellar (4), neutrophil-rich (3), macrotrabecular massive (2), and clear cell HCC (1) with remaining cases (100) being conventional HCC, no special type.

Conclusion

The study demonstrates the feasibility of subtyping HCC (as per the current WHO classification) for the first time on FNAB with cell blocks that carries implication for prognostication and emphasizes the importance of obtaining tissue diagnosis by FNAB with cell blocks.