Beware of the shrunken gallbladder – Case report of intraoperatively diagnosed gallbladder agenesis

INTRODUCTION AND IMPORTANCE: Gallbladder Agenesis, the congenital absence of the gallbladder, is a very rare biliary anomaly found in 13 to 65 people per 100,000. Symptomatic patients usually present with abdominal pain, nausea, and emesis, and are often misdiagnosed with gallbladder pathologies leading to unnecessary operations. CASE PRESENTATION: We report the case of a 63-year-old Caucasian female patient who presented with recurrent right upper quadrant pain (RUQ) and found to have a contracted gallbladder on ultrasonography (US). A hepatobiliary iminodiacetic acid (HIDA) scan was positive, and the patient was misdiagnosed with chronic cholecystitis. No gallbladder was found on laparoscopy and patient was diagnosed intraoperatively with gallbladder agenesis. Normal biliary anatomy was confirmed intraoperatively using the Firefly technique and there was no ectopic gallbladder on computed tomography (CT) scan obtained postoperatively. Patient currently doing well on conservative pain management. CLINICAL DISCUSSION: Patients with gallbladder agenesis and normal bile ducts often have symptoms similar to that of usual gallbladder problems. Accurately diagnosing these patients preoperatively remains a challenge. CONCLUSION: Symptomatic patients with agenesis of the gallbladder are often diagnosed intraoperatively despite major advances in diagnostic imaging techniques. In these cases, minimizing the risk of injury to the biliary tree is crucial. As our case demonstrates, it is critical for surgeons to become increasingly aware of this rare and important congenital anomaly. A very high index of suspicion is warranted in patients with a shrunken or contracted gallbladder. When in doubt, obtain cross-sectional imaging.