Gallbladder volvulus: it's a small whirl

An 85-year-old female with an extensive past medical history attended our accident and emergency department with vague abdominal pain and distension. Clinical examination and initial blood tests demonstrated features of sepsis and she was commenced on broad spectrum antibiotics. Following admission, a contrast-enhanced CT scan of the abdomen and pelvis was performed, which showed an unusual configuration of the gallbladder. There was significant luminal distension of the gallbladder, which was found to lie in an unusual horizontal position anterior to the liver edge. This was a new finding compared with a recent CT pulmonary angiogram that demonstrated a normal gallbladder anatomy. In addition, there was abrupt angulation of the gallbladder neck, demonstrating a "beak" sign as well as indrawing of the vascular pedicle forming a mini "swirl" sign. The constellation of gallbladder distension, abnormal lie, "beak" and mini "swirl" sign together is a strong indicator of gallbladder torsion. Coexistent right lower lobe pneumonia was noted. The patient was too frail for surgical intervention and succumbed to underlying sepsis. Post-mortem examination demonstrated a gangrenous gallbladder secondary to volvulus. We present a rare case of gallbladder volvulus and highlight CT findings to help the radiologist make a pre-operative diagnosis.