Category: Pituitary Disorders/Neuroendocrinology

Monitor: 8

8 - A GASTRINOMA PRESENTING AS DIARRHEA AND GI BLEEDING

Thursday, Apr 25
1:00 PM – 1:30 PM

Objective : To present the diagnosis of a neuroendocrine tumor (NET) over a series of admissions—accurate diagnosis requires follow-up, review of the patient’s history, and consideration of zebras amongst the horses.


Methods : n/a


Results :

A 64-year-old man with DM2, CKD3, NICM, and a history of an upper GI bleed presented with (p/w) 3-day history of watery diarrhea without blood or melena.  Initial lab results were remarkable for bicarbonate of 10.8 mEq/L (23-28) and alkaline phosphatase of 729 U/L (30-120).  His chart showed that 8 months prior to admission (PTA) he p/w hematemesis and declined endoscopy.  An abdominal ultrasound (US) had shown multiple 3-6 cm hepatic masses and limited view of a normal-appearing pancreas. Five months PTA, he p/w a CHF exacerbation complicated by hematemesis; EGD showed gastric body erosions and erythema, adherent clot, and blood in the stomach.  Repeat US showed stable hepatic masses concerning for metastatic process.  Endoscopic US 1 month PTA showed a 2.8 x 1.8 cm pancreatic mass in the body and tail; biopsy revealed atypical degenerated cells. A PET/CT showed no hypermetabolic activity. Subsequent liver biopsy diagnosed neuroendocrine carcinoma (NEC) likely of pancreatic origin. Endocrinology was consulted; lab tests revealed gastrin 882 pg/mL (0-115), VIP 130.4 pg/mL (0-58.8), chromogranin A 414 nmol/L (0-5), pancreatic polypeptide 36,687 pg/mL (0-418), iPTH 146 pg/mL (15-65), 25-OH Vit D 9 ng/mL (30-100), and normal glucagon and insulin.  The patient established outpatient care at another institution for treatment.  Surgery is preferred for localized disease and is considered in metastatic disease for the primary tumor and for confined hepatic metastases.  Medical therapy for metastatic disease ranges from streptozocin and doxorubicin-based chemotherapy to temozolomide and capecitabine along with inhibitors of mTOR, tyrosine kinase, growth factor, and/or angiogenesis.


Discussion : Initial presenting symptoms of NET align with common etiologies; NET became the working diagnosis after ruling out infection. The two specific considerations were VIPoma and gastrinoma.  The rarer VIPoma often causes flushing, muscle cramps, and hypochlorhydria; as a result, abdominal pain, heartburn, or GI bleeding are unlikely. With an incidence of 25-50 per million, NET are an infrequent cause of diarrhea.


Conclusion : Acute secretory diarrhea without infection makes NET a consideration. The presence of liver masses and a pancreatic mass is common for NET and particularly gastrinomas.  Review of previous symptoms of abdominal pain, dyspepsia, and upper GI bleeding then became strongly suggestive of gastrinoma which was then confirmed with lab work.

SHORT URL FUNCTION-->

Tyler S. Thompson

Physician, Internal Medicine
Novant Health: Winston-Salem Health Care
Lewisville, North Carolina

Dr. Tyler Thompson is board-certified in Internal Medicine practicing at Novant Health: Winston-Salem Health Care in Winston-Salem, NC where he practices primary care internal medicine. He obtained his medical degree from the University of Kentucky College of Medicine and completed his residency in internal medicine at George Washington University.

Michael S. Irwig

Associate Professor of Medicine
George Washington University

Michael S. Irwig, MD, F.A.C.E., is board-certified in Endocrinology & Metabolism and is an associate professor of Medicine at The George Washington University School of Medicine & Health Sciences. He also is an adjunct associate professor of Medicine at Georgetown University School of Medicine

Dr. Irwig is a general endocrinologist with a particular interest and expertise in androgens and transgender care. His research has focused on men with persistent sexual and non-sexual side effects of finasteride (Propecia), transgender health and men with borderline testosterone levels. He has over 30 peer-reviewed publications appearing in multiple journals including Current Opinion in Endocrinology, Diabetes and Obesity, Diabetic Medicine, Endocrine Practice, JAMA Dermatology, Journal of Clinical Endocrinology and Metabolism, Journal of Clinical Psychiatry, Journal of Sexual Medicine, Lancet Diabetes & Endocrinology and Nature Reviews Urology. His research findings have been featured in many national and international mainstream publications and broadcast outlets including: The Today Show, NBC Nightly News, ABC World News, CBS News, MSNBC.com, CNN, Men’s Health Magazine, Men’s Journal and The Philadelphia Inquirer.

Dr. Irwig has presented over 100 lectures at hospitals and medical schools across the world on several topics including male hypogonadism and transgender health. He also serves as a reviewer for over 36 peer-reviewed medical journals.

He is the past president of the mid-Atlantic chapter of the American Association of Clinical Endocrinologists (AACE). He serves on national committees for AACE as well as the Endocrine Society, including the Endocrine Self-Assessment Committee (ESAP).

Dr. Irwig received his M.D. degree from Cornell University and completed his residency in internal medicine at the University of Virginia. He was a senior fellow in endocrinology, metabolism, and nutrition at the University of Washington in Seattle.

Dr. Irwig does not accept any funding from pharmaceutical companies.

Tyler S. Thompson

Physician, Internal Medicine
Novant Health: Winston-Salem Health Care
Lewisville, North Carolina

Dr. Tyler Thompson is board-certified in Internal Medicine practicing at Novant Health: Winston-Salem Health Care in Winston-Salem, NC where he practices primary care internal medicine. He obtained his medical degree from the University of Kentucky College of Medicine and completed his residency in internal medicine at George Washington University.