A 70 year old lady presents with right upper abdominal pain for 1 day, which was severe and persistent, with radiation to the back. She also experienced a low grade fever, nausea, and several bouts of vomiting during the same period.

This is her first such episode, and her medical and surgical histories are unremarkable, with no history of diabetes, tuberculosis or peptic ulcer disease.

Her family history is unremarkable and she does not smoke, consume alcohol or abuse recreational drugs.

A complete blood count, liver profile, and renal profile are all normal, while a random capillary glucose level is 105 mg/dL. Serum amylase and lipase are reported to be 1280 U/L and 1100 U/L respectively.

Urgent ultrasonography of abdomen reveals a normal hepatobiliary tract; the pancreas could not be visualized clearly.