Surgicopathological classification of hepatic space-occupying lesions：A single-center experience with literature review

Accompanying rapid developments in hepatic surgery,the number of surgeries and identifications of histological types of primary hepatic space-occupying lesions （PHSOLs） have increased dramatically.This has led to many changes in the surgicopathological spectrum of PHSOLs,and has contributed to a theoretical basis for modern hepatic surgery and oncological pathology.Between 1982 and 2009 at the Eastern Hepatobiliary Surgery Hospital （EHBH） in Shanghai,31 901 patients underwent surgery and were diagnosed as having a PHSOL.In this paper,we present an analysis of the PHSOL cases at the EHBH for this time period,along with results from a systematic literature review.We describe a surgicopathological spectrum comprising more than 100 types of PHSOLs that can be stratified into three types：tumor-like,benign,and malignant.We also stratified the PHSOLs into six subtypes derived from hepatocytes;cholangiocytes;vascular,lymphoid and hemopoietic tissues;muscular,fibrous and adipose tissues;neural and neuroendocrine tissues;and miscellaneous tissues.The present study provides a new classification system that can be used as a current reference for clinicians and pathologists to make correct diagnoses and differential diagnoses among various PHSOLs.