Liver transplantation for advanced-stage primary hepatic yolk sac tumor: A case report and literature review

Primary hepatic yolk sac tumors (YSTs) are rare in adults. Liver resection is an acknowledged treatment modality for primary hepatic YST. Liver transplantation may offer a possible cure for unresectable cases. We present a case of a 31-year-old woman with an abdominal mass who had abnormally elevated alpha-fetoprotein (AFP) levels (31,132 ng/mL; normal: 0-7 ng/mL). Contrast-enhanced computed tomography (CT) revealed large tumors located in both lobes of the liver, with arterial enhancement and venous washout. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT indicated increased 18F-FDG uptake (maximum standardized uptake value, 24.4) in the liver tumors and left middle intra-abdominal nodule. The diagnosis was primary hepatic YST with metastasis to the greater omentum. The patient underwent orthotopic liver transplantation and intra-abdominal nodule resection after transarterial chemoembolization (TACE) as a bridge. Intraoperatively, an intra-abdominal nodule was confirmed in the greater omentum. Histopathological examination of the liver tumors revealed Schiller-Duval bodies. The tropomyosin receptor kinase (TRK) inhibitor larotrectinib was administered, followed by four cycles of chemotherapy with bleomycin, etoposide, and cisplatin based on the next-generation sequencing results. The AFP level decreased to within the normal range. No evidence of tumor collapse was observed during the 34-month follow-up period. This case suggests that multimodal therapy dominated by liver transplantation, including preoperative TACE, postoperative adjuvant chemotherapy, and TRK inhibitors, is an effective treatment modality for unresectable primary hepatic YST.