Abstract
RATIONALE: Primary hepatic neuroendocrine carcinoma (PHNET) is an exceptionally rare malignancy with limited standardized treatment options. PATIENT CONCERNS: Two patients presented with incidentally detected hepatic masses and nonspecific gastrointestinal symptoms. DIAGNOSES: Case 1 was diagnosed as primary hepatic neuroendocrine carcinoma (NEC, G3), and Case 2 as primary hepatic large-cell neuroendocrine carcinoma (LCNEC, G3), based on histopathology and immunohistochemistry after excluding extrahepatic origins. INTERVENTIONS: Case 1 received transarterial chemoembolization (TACE), etoposide-cisplatin chemotherapy, hepatic arterial infusion chemotherapy (HAIC), and octreotide. Case 2 underwent 3 cycles of drug-eluting bead TACE (d-TACE), HAIC, and long-acting octreotide for symptomatic control of diarrhea. OUTCOMES: Case 1 experienced progressive disease and died of sepsis. Case 2 achieved significant tumor regression, allowing curative resection. No recurrence was observed at one-month follow-up. LESSONS: The combination of d-TACE, HAIC, and octreotide may provide a potential downstaging approach for unresectable PHNET, but evidence remains preliminary and hypothesis-generating.