What is one of the diagnostic criteria for glucagonoma?

In the evaluation of glucagonoma, elevated glucagon levels serve as a key diagnostic criterion. Glucagonoma is a rare neuroendocrine tumor of the pancreas that secretes excessive amounts of glucagon, leading to a spectrum of symptoms, including hyperglycemia, weight loss, and characteristic skin lesions known as necrolytic migratory erythema. Measuring serum glucagon levels is instrumental in confirming the diagnosis, as individuals with glucagonoma typically present with significantly elevated levels that are substantially higher than normal physiological ranges.

This elevation in glucagon occurs as a result of the tumor's secretory function, distinguishing glucagonoma from other conditions where hormone levels may differ. Recognizing elevated glucagon levels is crucial for establishing a clear diagnosis and subsequently guiding appropriate management. Other options lack specificity or relevance to the direct measurement of glucagonoma, making the detection of elevated glucagon levels the most pertinent diagnostic aspect.