Paediatric gallbladder volvulus

A 5-year-old male presented to the Children's Emergency Care (CEC) service with a one-day history of initial periumbilical pain that localized to the right iliac fossa (RIF). He had a reduced appetite, increasing fatigue and vomited once at CEC. His parents reported no fevers, cough, coryza or bowel and urinary symptoms. On examination, his abdomen was soft and tender in the RIF, with no peritonism or palpable masses, and his testes were normally aligned. Blood tests showed a raised C-reactive protein (15 mg/L) and neutrophils (8.7 × 10(9)/L) with all other results, including liver function tests, being within reference range. Abdominal ultrasound showed inflammatory changes in the RIF, with the appendix unable to be visualized and marked mural thickening of the gallbladder without calculi or focal tenderness to scanning. Despite the gallbladder findings, further pre-operative imaging was not undertaken, as given the patient's demographic and presentation, it was felt appendicitis was the most likely diagnosis. A laparoscopic appendicectomy was initially planned, but on visualization of the appendix, it appeared non-inflamed. However, the gallbladder appeared haemorrhagic, ischaemic and was mobile, having volved on the cystic duct and artery ~720 degrees (Fig. 1). The gallbladder was decompressed, de-volved (Figs 2, 3) and a cholecystectomy plus appendicectomy was completed. Although an alternative diagnosis to appendicitis was found, the decision to remove the appendix was made following a discussion with the patient's parents intraoperatively. Histology of the gallbladder showed markedly ischaemic tissue with total transmural infarction. The patient recovered well and was discharged home on day two post-op. There are only ~500 cases of gallbladder volvulus reported in English literature.1 85% of cases reported are between the ages of 60 and 80 years, making this condition exceedingly rare in the paediatric population.2 The pathogenesis of gallbladder volvulus is unknown, but proposed mechanisms include congenital anatomical variations of the gallbladder mesentery and absence of supportive tissues.3 Congenital anatomical variants likely cause gallbladder volvulus in the paediatric population and are consistent with the findings of a mobile gallbladder in this patient.3, 4 Less than 10% of patients are diagnosed preoperatively with gallbladder volvulus, partially due to its similar presentation to acute cholecystitis.5 Unlike this patient, gallbladder volvulus can also present with fever, palpable mass and jaundice, alongside abdominal pain and nausea plus vomiting.3-5 The challenge with gallbladder volvulus is its non-specific clinical, laboratory and radiological findings which can’t be distinguished from acute cholecystitis.2, 3 In the paediatric population this is further complicated due to the difficulty in obtaining a clear history. Several paediatric case reports discuss the initial misdiagnosis of acute cholecystitis leading to a delay in treatment.2, 4, 6 This case demonstrates a unique initial presentation resembling acute appendicitis, further highlighting the variable presentation of gallbladder volvulus. Although it is a rare diagnosis in the paediatric population, gallbladder volvulus should be considered in the differential when there is diagnostic uncertainty. Signed written informed consent was given by the legal guardian of the patient for the publication of the manuscript and supporting figures.