Omental torsion masquerading as cholecystitis in a patient with gallbladder agenesis.

Abstract

We report a case of omental torsion and agenesis of the gallbladder diagnosed intra-operatively in a 42-year-old man who presented to the emergency department with a five-day history of worsening right upper quadrant abdominal pain, radiating to the back, associated with oral food intake and exacerbated by deep inspiration. This was on a background history of hypercholesterolaemia and hypertension, with a strong family history of symptomatic gallstones. He had no history of abdominal surgeries. On examination, the patient had right upper quadrant abdominal tenderness and a negative Murphy's sign. Systemically, he was afebrile and haemodynamically stable. Blood tests revealed an elevated C-reactive protein of 35 mg/L and a mildly elevated total bilirubin of 22 μmol/L. The following values were within normal range: a lipase of 27 U/L, an alanine transaminase of 37 U/L, aspartate transaminase of 28 U/L, alkaline phosphatase of 61 U/L, and gamma-glutamyl transferase of 44 U/L. The white cell count was normal at 8.5 × 109/L. Transabdominal ultrasound of the biliary tract was reported with an impression of multiple stones within a grossly distended gallbladder (Fig. 1). The gallbladder walls were reported as thickened up to 5 mm. This clinical picture combined with characteristic imaging findings met the Tokyo guidelines criteria for a ‘definite’ diagnosis of acute cholecystitis, so we proceeded to laparoscopic cholecystectomy and the patient was placed on intravenous piperacillin/tazobactam pre-operatively.1 On laparoscopy, the gallbladder could not be identified on exploration of the liver bed (Fig. 2). Inferior to the lower border of the liver, a mass of torted and infarcted omentum was visualized (Fig. 3). This tissue was resected and secured using LigaSure. The patient was discharged Day 1 post-operatively with oral analgesia and is now pain free. Gallbladder agenesis is a rare anatomical variant, with an incidence of 10–65 cases per 100 000. Some patients may present with symptoms that maybe mistaken for biliary symptoms, despite the absence of a gallbladder. These patients may be misdiagnosed with gallbladder pathology following ultrasound and subsequently proceed to surgery.2 It is reported that 50% of cases of gallbladder agenesis are diagnosed on laparoscopy.3-8 This presents an opportunity to avoid unnecessary surgery through improved diagnostic workup. Malde proposes the routine investigation of biliary colic with magnetic resonance cholangiopancreatography (MRCP) as first-line in patients with unidentified or shrunken gallbladder on transabdominal ultrasound.9 The utilization of MRCP prior to cholecystectomy may avoid unnecessary operative risks. In this case however the torted omentum masqueraded as an inflamed gallbladder full of gallstones such that an alternative diagnosis was not pursued. Open access publishing facilitated by The University of Queensland, as part of the Wiley - The University of Queensland agreement via the Council of Australian University Librarians. Raima Reza: Writing – review and editing. Thomas Anglim Lagones: Writing – original draft.