Initial workup was negative for viral, bacterial, parasitic, inflammatory, osmotic, and malabsorptive etiologies of diarrhea. Patient’s laboratory workup was significant for electrolyte disturbances including hypokalemia, hyponatremia (K 2.6, Na 127) and Vasoactive Intestinal Peptide (VIP) of 1930 (normal 0-60).

The patient underwent an ultrasound guided liver biopsy of a liver lesion seen on CT. Pathology results from patient's liver biopsy showed metastatic neuroendocrine cells in the liver representing a tumor arising from the endocrine pancreas (VIPoma).