Brief Answer:
Cause of weight loss to be found out, other factors to be ruled out.

Detailed Answer:
Hi.
Thanks for your information.

To recapitulate: Female/62 (visited a Doctor/Medication tried - please provide the full details) - EUS shows atrophy of entire pancreas (parenchymal abnormality)- heperechoic wall of the pancreatic duct but only in the head part - duct up to 4 mm - weight loss of 40 pounds over 8 weeks -

From the history you have provided it appears that due to atrophy of the pancreas the digestive enzymes which the pancreas produces to digest the food must have been reduced drastically not allowing the food to be digested in the small intestine. This may be the major reason of weight loss.

Another reason can be diabetes caused due to the atrophy of the pancreas and hence the reduction of the production of insulin.

I would advise you the following:
Check for blood sugar levels and if there is elevated blood sugars, you may need to take insulin.
Addition of Pancreatic enzymes with the foods, every time.
Further tests like CT scan of the whole abdomen to rule out any hidden malignant tumors or so.
Upper GI endoscopy to see coexisting gastritis or ulcers.
And others as may be advised by your Gastroenterologist.
So much weight loss in just 8 weeks is a point to be investigated thoroughly.

I hope this answer helps you to get a proper diagnosis, and get a proper further treatment. Please feel free to ask for more if you need to or if you feel that there is a gap of communication.

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