Duplication of IVC discovered incidentally during neuroblastoma resection surgery: a rare case report

Introduction: Duplication of the inferior vena cava (IVC) is a rare congenital venous anomaly with significant implications in retroperitoneal and oncologic surgery. Failure to identify this anomaly preoperatively may increase risks such as intraoperative bleeding, incomplete tumor resection, and vascular injury. We report a case of a 12-year-old boy with a large right adrenal neuroblastoma complicated by an unrecognized duplicated IVC encountered during surgery. Case presentation: The patient underwent neoadjuvant chemotherapy followed by surgery. During laparotomy, two distinct right and left IVC channels were seen joining below the liver. Dense adhesions between the tumor, duplicated IVC, and adjacent vessels prevented safe complete tumor excision; only partial debulking and lymph node sampling were performed. Postoperative recovery was uneventful. Histopathology confirmed neuroblastoma with extensive tumor necrosis and nodal metastases. Discussion: IVC anomalies such as duplication stem from abnormal embryological development of cardinal and subcardinal veins. Although often asymptomatic and found incidentally, duplicated IVCs critically alter surgical landmarks and elevate bleeding risk during retroperitoneal procedures. Preoperative detection via imaging is vital, especially in oncologic resections involving large adrenal or retroperitoneal tumors near major vessels. Recognizing vascular variations facilitates better surgical planning, including adapting dissection techniques, arranging vascular surgery backup, and counseling about resectability prospects. Conclusion: This case emphasizes the need for thorough preoperative imaging to identify IVC variants and multidisciplinary planning to minimize intraoperative complications and improve surgical outcomes.