Interpretation of core biopsy of liver mass lesions: A comparison study between cytopathologist and gastrointestinal pathologist

Context: Core biopsy (CB)is a main tool for diagnosis of liver mass lesions. When CB is performed with fine needle aspiration (FNA), the CB may be interpreted by a cytopathologist or gastrointestinal pathologist. Objective: This study compares interpretation of liver mass biopsy between cytopathologist and gastrointestinal pathologist in the era of subspecialty practice. Design: 349 liver mass lesions with FNA and CB performed during a 5-year period were retrieved. All cases were initially interpreted by a cytopathologist and retrospectively reviewed by a gastrointestinal pathologist. Results: The overall agreement was 95.1% (332/349 cases). There was agreement on 57/65 non-neoplastic cases (87.7%)with 8 (12.3%)discordant cases including 4 steatosis (steatohepatitis missed in 3 cases, 1 re-interpreted as focal nodular hyperplasia [FNH]); 3 inflammation (1 necrotizing granulomatous inflammation, 1 massive necrosis instead of fibrosing cholestatic hepatitis, and 1 hepatocellular carcinoma [HCC]was missed); and 1 initially deemed normal re-interpreted as FNH. There was agreement on 275/284 neoplastic cases (96.8%), with 9 (3.2%)discordant cases including: 2 initially interpreted as HCC (1 metastatic adrenal cortical carcinoma, 1 cholangiocarcinoma); 3 adenocarcinomas (2 further defined as prostatic primary, 1 well-differentiated neuroendocrine tumor [WDNET]); 2 metastatic carcinomas (1 tumor-induced fibrosis instead of cirrhosis, 1 LCNEC re-interpreted as WDNET); 1 poorly differentiated carcinoma (re-interpreted as LCNEC); and 1 sarcomatoid carcinoma (re-interpreted as leiomyosarcoma). Conclusion: Cytopathologist and gastrointestinal pathologist are highly concordant in the interpretation of neoplastic liver mass CB. Consultation may improve accuracy in certain non-neoplastic biopsies and neuroendocrine neoplasms.