Two closely neighboring hepatocellular carcinomas mimicking intrahepatic metastasis are confirmed as double primary tumors by the loss of heterozygosity analysis of microsatellites

Hepatocellular carcinoma （HCC） is a common malignancy around the world.Among all HCCs,multifocal HCC accounts for 12%-19%.1 The origin of multifocal HCC can either be the intrahepatic metastasis of a single tumor clone,or independent primaries.2 It is crucial to distinguish intrahepatic metastatic tumor from multicentric HCC because this distinction has significant impact on tumor staging,treatment plan,and clinical outcome.Routine histological examination alone cannot determine the clonal origin of multifocal HCC and usually results in their arbitrary classification as satellite nodules.The only way to reliably determine clonality among multiple lesions is by molecular genetic analysis.We report a patient who underwent surgical resection for two neighboring hepatocellular carcinomas that were from independent primaries.These separate nodules mimicked a solitary primary with intrahepatic metastasis.Confirmation of separate clones was established by the loss of heterozygosity （LOH） of microsatellites.