ABSTRACT
BACKGROUND/AIMS: Noninvasive diagnostic criteria for hepatocellular carcinoma (HCC) differ between guidelines, especially for subcentimeter-sized nodules. This study aimed to analyze clinical and radiological characteristics of subcentimeter-sized HCC, and assess the validity of noninvasive diagnostic criteria of the revised 2014 the Korean Liver Cancer Study Group and the National Cancer Center (KLCSG-NCC) guideline for subcentimeter-sized HCC. METHODS: A total of 33 consecutive patients (median age, 58.6 years; men, 60.6%; hepatitis B virus-infected, 87.9%) who were diagnosed with HCC between January 2009 and December 2013 and had a maximum tumor diameter less than 1 cm were retrospectively included. RESULTS: Among 33 subcentimeter-sized HCC cases, 6 cases were histologically proven and the remaining 27 patients were diagnosed by radiologically and/or serologically. Initial detection modality was dynamic contrast-enhanced computed tomography (CT) (66.7%, 22/33) or dynamic contrast-enhanced magnetic resonance imaging (MRI) (33.3% 11/33). No case was identified by surveillance ultrasonography. Typical radiological feature of HCC, which is arterial enhancement with delayed washout, was present in 51.7% (15/29 patients) in dynamic contrast-enhanced CT, and 90.9% (30/33 patients) in dynamic contrast-enhanced MRI. When these 33 cases were re-assessed by the revised 2014 KLCSG-NCC guideline, no one has fulfilled the noninvasive diagnostic criteria. CONCLUSIONS: None of the cases that were diagnosed as subcentimeter-sized HCC including histologically confirmed cases did not fulfill the noninvasive diagnostic criteria of the revised 2014 KLCSG-NCC guideline. Refinement of the current noninvasive diagnostic criteria for subcentimeter-sized HCC may be required.