Small hepatocellular carcinomas in cirrhotic explant livers: Identification by macroscopic examination and lipiodol localization

Small hepatocellular carcinomas (HCCs) in cirrhotic livers are difficult to detect. This study aimed to assess if small HCCs can be better identified using specific macroscopic sampling criteria and Lipiodol (iodized oil) localization on radiographs, and to evaluate thereby their incidence and morphology. Prospective cirrhotic recipients of orthotopic liver transplantation (OLT) were administered hepatic arterial Lipiodol at angiography. Posttransplantation, the explant livers were sliced and inspected as per routine for unusual nodules. If unusual nodules were found or HCC clinically suspected, the slices underwent soft-tissue radiography. Tissue samples were then taken as per protocol from all nodules with diameter ≥1 cm/unusual appearance/exophytic bulge, and from foci of radiographic Lipiodol uptake or high soft-tissue density. One hundred three lesions were assessed and classified histologically as HCC (n = 55) or regenerative nodule (n = 39) or borderline (n = 9). Sampling according to predetermined macroscopic criteria proved an effective method for identifying small HCCs: 44 cancers were detected, most < 5 mm in diameter, additional to those picked up on routine assessment. Green nodules were more likely to be HCC (P < .0001). The cancers were all multifocal, and had characteristic histological features of HCC except for 12 unusual fibrotic cancers in livers with alcoholic cirrhosis. Lipiodolization alone identified one additional HCC. Lipiodol retention on x-ray is fairly specific for HCC (83%), and can even identify lesions 2 mm in diameter. But its sensitivity is poor (45%), and its routine use to identify HCCs in explant livers is not recommended.