Rationale: Neuroendocrine carcinoma originating from extrahepatic bile duct is very rare, and only a few cases have been reported. Because of its scarcity of incidence, not much is known about the disease but for its aggressiveness and poor prognosis. Patient concerns: In this report, we present 2 cases of large cell neuroendocrine carcinoma (LCNEC) originating from extrahepatic bile duct. Case 1: a 60-year-old woman presented with jaundice but no abdominal pain. Case 2: a 67-year-old man also presented with jaundice, along with abdominal discomfort and appetite loss. Diagnoses: Case 1: LCNEC with a focal adenocarcinoma component (pT2aN1M0, pStage IIIB). Case 2: LCNEC with a focal adenocarcinoma component (pT1N1M0, pStage IIB). Interventions: Case 1: the patient underwent left hepatectomy and caudatectomy with hepaticojejunostomy, followed by 6 cycles of adjuvant chemotherapy (etoposide and cisplatin). Case 2: the patient underwent laparoscopic pylorus–preserving pancreatoduodenectomy, followed by 6 cycles of adjuvant chemotherapy (etoposide and cisplatin). Outcomes: Case 1: liver metastasis was detected 6 months postoperatively, and despite multiple chemotherapy regimens, the patient died 24 months post-surgery. Case 2: liver metastasis was detected 23 months postoperatively. The patient is still alive 36 months post-surgery after receiving multiple chemotherapy regimens and radiotherapy. Lessons: Given the rarity of LCNEC, it is essential to continue collecting and reporting additional case studies to build a more comprehensive understanding of the disease. Although the prognosis for LCNEC is generally poor, the use of a multidisciplinary approach and further research will be critical in developing more effective treatment strategies in the future.

Background: Patients with acute cholecystitis (AC) often receive antibiotics to reduce the risk of infectious complications after cholecystectomy. This study investigated the clinical significance of antibiotic use in patients with mild-to-moderate AC who required emergency laparoscopic cholecystectomy. Methods: This multicenter, double-blind, randomized controlled trial was conducted at four centers between February 2023 and January 2024. Patients with AC eligible for emergency laparoscopic cholecystectomy were randomly assigned to the antibiotic or placebo group. The antibiotic group received 1 g of intravenous cefazolin daily for three days during hospitalization and oral antibiotics for 4 days after discharge, whereas the placebo group received 10 mL of intravenous normal saline during their hospital stay. The primary endpoint was the rate of infectious complications. Results: An imputed per-protocol analysis of 370 patients (185 in each group) found comparable postoperative infection rates between the antibiotic group (7.6%, 14 patients) and placebo group (7%, 13 patients), showing no statistically significant difference (P = 0.842). Overall, the non-infectious complication rates did not differ significantly between the two groups: 21 (11.5%) cases in the antibiotic group vs. 30 (16.2%) cases in the placebo group (P = 0.591). Considering a non-inferiority margin of 10%, the absence of antibiotic treatment did not result in worse clinical outcomes than the antibiotic treatment. Conclusions: Administering antibiotics, even in sufficient doses, did not significantly reduce the risk of infectious complications in patients with AC compared to the group that did not receive antibiotics.