Jeon Y, et al. - In view of the findings that the macrotrabecular (MT) pattern of hepatocellular carcinoma (HCC) represent a distinct HCC subtype, researchers evaluated 231 HCC cases regarding histologic patterns, including MT-pattern. Presence of trabeculae >6 cells thick defined MT-pattern. Controls comprised cases deemed conventional HCC (CV-HCC) following exclusion of all recognized HCC subtypes. In 41 (17.7%), 24 (10.4%) and 4 (1.7%) cases, HCCs with a component of ≥10%, ≥30% and ≥50% MT-pattern were noted, respectively. HCCs with 10% to 29% MT-pattern (n=17, 7.4%) had clinicopathologic features largely similar to CV-HCC. The 30% and 49% (n=20) and ≥50% (n=4) MT groups showed no significant difference, hence were combined for further analysis as MT-HCC. Compared with CV-HCC, MT-HCCs (≥30% MT-pattern) were noted to be larger tumors (5.5 vs 3.1 cm), were less frequently associated with cirrhosis (54% vs 79%), were more frequently with hepatitis B (21% vs 5%) and less frequently with hepatitis C infection (33% vs 58%). The presence of anaplastic tumor cells (42% vs 14%), higher alpha-fetoprotein level, higher AJCC stage, and higher histologic grade were noted in crrelation to MT-HCC. They noted poorer overall survival among patients with MT-HCC vs patients with CV-HCC. A higher recurrence rate and worse recurrence-free survival were evident in patients with MT-HCC who underwent primary resection or transplantation. The findings suggest the possible utility of ≥30% MT-pattern as the more appropriate cut-off for defining MT-HCC, which represents a unique and aggressive HCC histologic subtype.