PLA2G2A is associated with an inflammatory hepatocellular adenoma

Benign hepatocellular adenomas (HCA), which are very rare, have recently been observed in patients with diabetes mellitus, but most of them have been resected in consideration of the possibility of the progression to hepatocarcinoma (HCC). This is due to the limited study for subtyping of HCC and the lack of molecular biological insights into the carcinogenic potential of benign tumors. To update the subtype classification of HCA, especially I-HCA which occupy over 35% of all HCAs, the comparison of gene expression profiling between I-HCA and HCC with normal liver tissues was analyzed. Single-cell RNA-sequencing (scRNA-seq) following to immunohistochemistry of I-HCA tissues indicated that the phospholipase A2 group IIA (PLA2G2A) mRNA and protein were specifically localized in hepatocytes of I-HCAs rather than other representative markers of I-HCA. The result of RNA-seq from formalin-fixed paraffin-embedded (FFPE) of other I-HCAs proofed the limited and high expression of PLA2G2A. From the clinical database, PLA2G2A expression in HCC did not correlate with poor prognosis. This finding has the potential to develop into a new definition of I-HCA, resulting in a significant clinical contribution.