Gall Bladder Agenesis: A Rare Embryonic Cause of Recurrent Biliary Colic.

BACKGROUND Gallbladder agenesis (GA) is an extremely rare anatomic anomaly with a reported incidence of less than 0.5%. It is usually asymptomatic, but can present with features of biliary colic and cholecystitis. We present here a case of GA in a patient with recurrent biliary colic.  CASE REPORT A 24-year-old African American woman presented with recurrent episodes of right upper-quadrant abdominal pain. During her first episode, she was found to have elevated transaminases and clinical features of cholecystitis, but ultrasound did not visualize a gallbladder and she was discharged with a diagnosis of biliary colic. She returned within a week with worsening liver enzymes, severe pain, and vomiting. A hepatobiliary iminodiacetic acid (HIDA) scan was done, which again did not show the gall bladder. On clinical suspicion of acute cholecystitis, she underwent laparoscopic surgery. Intraoperatively, the gall bladder fossa was empty and a diagnosis of gall bladder agenesis was made. She presented a third time with similar complaints and magnetic resonance cholangiopancreatography (MRCP) was done, which showed normal biliary tract anatomy and absent gall bladder. A diagnosis of sphincter of Oddi dysfunction was made and she was discharged on antispasmodics. CONCLUSIONS Diagnosing GA is challenging. The rarity of this entity combined with classic clinical features of cholecystitis and non-visualization of the gall bladder on routine investigation prompts unnecessary surgical intervention. Awareness of this condition, along with use of better imaging modalities like preoperative MRCP, can aide physicians to appropriately manage this uncommon clinical condition.