Experts' POV

Gastroenterologists see a lot of patients with chronic diarrhea. Most of them will have conditions such as irritable bowel syndrome, but we know that occasionally the diagnosis will be something less common such as a neuroendocrine tumor syndrome. I think gastroenterologists want to be better educated about how to recognize these patients and what, at least, the first steps in the diagnostic evaluation should be.

Typically, patients may have been investigated elsewhere by other specialists because of diarrhea. Either no clear diagnosis may have been found or the patient may have been given the diagnosis of irritable bowel syndrome or functional diarrhea, for example. What I or my colleagues would do in that situation would be to take a careful clinical history from the patient, examine the patient, and during the history look for any other possible pointers toward a functional neuroendocrine tumor syndrome. If there was a index of suspicion there, then we would do appropriate diagnostic testing to try and rule in or rule out that possibility and typically that would be a serum chromogranin A and/or a 24-hour urinary 5-hydroxyindoleacetic acid collection. Sometimes with a bit of thought and imagination, the gastroenterologists may consider the possibility of a functional neuroendocrine tumor syndrome and may be the person to establish the diagnosis in those patients

Once the patient has been diagnosed—for example, a patient with typical clinical features and a markedly elevated CgA level—the first challenge is to try and locate the tumor. If the tumor was accurately localized and the patient was a good candidate for surgery, then probably I would be having a discussion with a surgeon about the appropriate approach to resection. If, on the other hand, there was evidence of marked tumor spread and/or if the patient was not a particularly good candidate for surgery, then probably I would be speaking with my colleagues in oncology about their recommendations for further management.