Combined Hepatocellular-Cholangiocarcinoma With Ductal Plate Malformation Pattern: A Case Report With Molecular Analysis

Combined hepatocellular-cholangiocarcinoma with a ductal plate malformation pattern is an extremely rare entity with unelucidated pathogenesis. We present the case of a 60-year-old male patient who underwent a sectionectomy for pre-operative diagnosis of hepatocellular carcinoma based on clinical and image findings. Gross examination of the specimen revealed a well-defined tumor with cystic change measuring 6.7 x 6.2 cm. Microscopically, the lesion had classical features of hepatocellular carcinoma and intrahepatic cholangiocarcinoma exhibited neoplastic glands with irregular-sized dilated lumens, resembling a ductal plate malformation. Postoperative diagnosis was combined hepatocellular-cholangiocarcinoma with ductal plate malformation pattern. Next-generation sequencing revealed genomic alteration in 15 genes: CDKN2A, CHD4, CYP2D6, ERBB3, KIR3DL1, KRAS, MDM2, PIM1, STAT6, TPMT amplification, FANCD2, FAT1, FLT4, RASA1, and TP53 point mutation. This is the first case report of molecular alteration in combined hepatocellular-cholangiocarcinoma with ductal plate malformation pattern.