Clinical outcomes of rare hepatocellular carcinoma variants compared to pure hepatocellular carcinoma Katerina Zakka,1 Renjian Jiang,2 Olatunji B Alese,1 Walid L Shaib,1 Christina Wu,1 Joel P Wedd,3 Marty T Sellers,4 Madhusmita Behera1,2, Bassel F El-Rayes,1 Mehmet Akce11Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA; 2Department of Research Informatics, Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA; 3Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA; 4Division of General and GI Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA, USABackground: HCC variants are rare primary hepatic tumors. The aim of this study is to compare clinical characteristics and outcomes of HCC variants with pure HCC.Methods: Patients diagnosed between 2004 and 2013 with ICD-O-3 8180/3 and 8170/3-8175/3 were identified from the National Cancer Database. Univariate and multivariate survival analyses were conducted to analyze the association between histology and overall survival (OS).Results: 80,280 patients were identified; pure HCC 78,461 (97.7%), fibrolamellar (FLHCC) 310 (0.4%), scirrhous 161 (0.2%), spindle cell 72 (0.1%), clear cell 487 (0.6%), pleomorphic 23 (0.0%), and combined HCC and cholangiocarcinoma (mixed HCC) 766 (1.0%). 76.7% were male and 72% Caucasian. Liver transplant was performed in 10.1% of pure HCC, 14.5% of mixed HCC, 16.2% of scirrhous, 6.9% of spindle cell, 8.8% of clear cell, 8.7% of pleomorphic, and 3.2% of FLHCC (p