FCP2-500

FCP2-500

A 47-year-old man is seen in clinic with a 3 month history of chronic epigastric discomfort. The pain comes and goes and radiates to his back and his right shoulder tip at times. It is worse after meals but there is no relieving factor. He feels nauseous most of the time and has foul-smelling stools. He has lost 2 stones in weight. He also complains of intermittent light-headedness. He drinks a bottle of wine on most nights and smokes 20 cigarettes /day.

On examination, he is thin and looks neglected. His abdomen is soft, but tender on deep palpation in the epigastric area. He has a 2 cm non-tender liver edge. He also has decreased sensation to light touch on both feet.

Bloods:
sodium 131 mmol/l
potassium 4.2 mmol/l
creatine 64 μmol/l
amylase 35 U/l
alanine aminotransferase (ALT) 104 U/l
alkaline phosphatase (ALP) 121 U/l
bilirubin 24 μmol/l
calcium 2.01 mmol/l
whole cell count (WCC) 12.1 × 109/l
haemoglobin (Hb) 10.2 g/dl
platelets 462 × 109/l
abdominal X-ray (AXR) normal
oesophago-gastro duodenoscopy (OGD) mild gastritis
Campylobacter-like organism (CLO) test negative
ultrasound abdomen mildly enlarged liver with fatty change
spleen and kidneys normal
pancreas partially obscured by overlying bowel gas
72-h stool fat 22 g in 72 h

He is referred for a secretin test:
volume collected 110 ml
bicarbonate 52 mEq/l

What is the most likely diagnosis?