I Have A Side 9mm Branch IPMN In Pancreas Body

I have a side 9mm branch IPMN in pancreas body stable for 2 years now from Nov. Also have Hashimoto's thyroid end stage & tiny. Also have NAFLD with mild fibrosis had biopsy last year. All liver numbers are normal. No Hepatitis Infections. Have 6mm gallstone stable 2 years. Just had CT for chest pain. Shows a 1.5cm lymph node at porta hepatis. All labs normal. What is most likely cause?