Pathological Complete Response After Conversion Surgery for Initially Unresectable Hepatocellular Carcinoma Followed by Alpha-Fetoprotein-Producing Jejunal Adenocarcinoma With Hepatoid Differentiation: A Case Report

Recent advances in systemic therapy have increased opportunities for conversion surgery in selected patients with initially unresectable hepatocellular carcinoma (uHCC).We report a rare case of initially unresectable advanced HCC with portal vein tumor invasion, multiple intrahepatic metastases, and extrahepatic metastases in which sequential immune-based systemic therapy enabled conversion surgery, with pathological examination confirming a complete response in the resected segment 2 lesion.Persistent alpha-fetoprotein (AFP) elevation after surgery initially raised concern for occult or recurrent HCC, but the subsequent detection of recurrent HCC and jejunal adenocarcinoma with hepatoid differentiation complicated this interpretation.After resection of both lesions, folinic acid (leucovorin), 5-fluorouracil, and oxaliplatin (FOLFOX) therapy for residual mesenteric lymph node lesions considered metastatic on imaging was followed by a marked decline in AFP and disappearance of the lymph node lesions.This case highlights the potential role of conversion surgery after systemic therapy in selected patients with initially unresectable HCC and the importance of interpreting persistent AFP elevation together with imaging, pathological findings, and the clinical course.