Ectopic liver tissue on the gallbladder wall with independent vascular supply: a case report.

Ectopic liver (EL) is hepatic tissue with no parenchymal or ductal continuity with the native liver, even though it may receive an aberrant arterial supply, including a branch arising from the hepatic arterial system. While the gallbladder serosa represents the most frequently reported site for this anomaly, cases presenting with a clearly identifiable, independent vascular supply remain uncommon in clinical practice, often posing a diagnostic challenge during routine hepatobiliary evaluations. A 65-year-old male presented with a 2-year history of intermittent right upper quadrant abdominal pain. Preoperative non-contrast computed tomography (CT) demonstrated a hyperdense lesion within the gallbladder measuring approximately 2.7 × 2.1 cm, consistent with cholelithiasis. Notably, the imaging also revealed an exophytic nodular measuring approximately 1.2 × 0.8 cm firmly attached to the serosal surface of the anterior wall near the fundus. The patient subsequently underwent indocyanine green (ICG) fluorescence-guided laparoscopic cholecystectomy. Intraoperatively, a small, well-circumscribed, liver-like nodule was identified on the gallbladder wall. Under real-time near-infrared fluorescence, the nodule retained ICG and fluoresced bright green, identical to the native liver. The anomaly was completely excised en bloc with the gallbladder to prevent tissue fragmentation. Subsequent histopathological evaluation confirmed normal hepatic lobules and portal triads, establishing a definitive diagnosis of true ectopic liver tissue. Distinguishing EL from accessory hepatic lobes is clinically crucial, our case confirms true EL through complete anatomical separation and independent vascular pedicle. This case underscores the importance of meticulous intraoperative exploration and highlights the utility of ICG fluorescence in ensuring clear visualization during surgical resection.