Introduction

Imaging modalities can predict histopathological characteristics of tumors such as cellularity and proliferation potential, which has also been shown for hepatocellular carcinoma (HCC). Diffusion-weighted imaging can reflect cellularity of tumors and provide apparent diffusion coefficient (ADC) values as a quantitative imaging marker. This analysis elucidates possible associations between ADC values and several immunohistochemical features of HCC.

Material and methods

A cohort of 25 patients (4 female; 16%) with a mean age of 63 ±8.9 years met the inclusion criteria of this analysis. The main inclusion criteria were the availability of an MRI pre-interventional examination within 9 months before surgery and the availability of the histopathologic analysis. Immunohistochemical features included programmed cell death-ligand 1 (PD-L1) scores (immune cell score [ICS], tumor proportion score [TPS], and combined positive score [CPS]), glypican-3, tumor-infiltrating lymphocytes (TIL), stroma infiltrating lymphocytes (SIL), CD68 positive cells and microvessel density (MVD). ADC values were measured as ADCmax, ADCmean, and ADCmin.

Results

CD3+ TIL showed a moderate inverse correlation with ADCmax (r = –0.50, p = 0.01), ADCmean (r = –0.52, p = 0.008). CD34+ MVD showed higher expression in the group that showed diffusion restriction (mean 40 ±10.8 vs. 54 ±5.5, p = 0.0046). There was no correlation between ADC values and CD68+ positive cells, PDL-1, glypican-3 expression, or CD3+ SIL.

Conclusions

The present analysis demonstrated an inverse correlation between CD3-positive tumor-infiltrating lymphocytes and ADCmean and ADCmax. Diffusion restriction is correlated with increased microvessel density in HCC. ADC values could help to better characterize the tumor microenvironment of HCC in a non-invasive manner.