In a previous post, we asked you to try to diagnose our patient, Mrs. C. What follows below is the actual diagnosis, but visit the previous entry if you want to see what folks guessed.
Did Mrs. C have a bug?
This winter season in Boston, we've been struck with an early and particularly vile spate of influenza cases that have filled hospitals to capacity and have Boston residents scrambling for vaccinations. What's unusual about this year's flu is that in addition to respiratory symptoms, many are suffering from gastrointestinal distress, including vomiting, abdominal cramps, and diarrhea.
The symptoms of this flu virus resemble those of another bug that sweeps through the city nearly every winter. That bug is norovirus, a fast-moving and highly infectious virus that causes 24 hours of vomiting and often violent diarrheal episodes. But both the flu virus and norovirus usually get better: these are examples of acute diarrheal illnesses, and for the most part, such viruses and their cousins are to blame for short-lived cases of diarrhea. Since these bugs can't be treated, doctors usually let acute diarrheal episodes resolve on their own, without aggressive treatment or further investigations.
Or was it something more sinister?
Chronic diarrhea is an entirely different circumstance. Diarrhea needs to last more than four weeks before it can be considered chronic. Mrs. C more than meets the definition -- she's had diarrhea for probably more than a decade. In developed countries such as the United States, people who have diarrhea off and on over a long period of time often suffer from irritable bowel syndrome (IBS), a disease that leads to an overactive and sensitive gut that may squeeze more often than it should. However, what raised flags for Mrs. C's gastroenterologist, Dr. Jacqueline Wolf at Beth Israel Deaconess Medical Center, was that these episodes started affecting her at night. Because stress is thought to be related to IBS, patients with this condition rarely present with diarrhea at night, when stress levels drop.
"When someone has unexplained chronic diarrhea," Dr. Wolf says, "or diarrhea occuring in the middle of the night, one has to think beyond irritable bowel syndrome." So that's what Dr. Wolf did. But even the other usual culprits of chronic diarrhea were nowhere to be found. Inflammatory bowel disease, an autoimmune disorder that leads to destruction of tissue in the gut, usually means that the patient passes blood in the stool. Colonoscopy and endoscopy results can show changes in the gut wall. But Dr. Wolf did not see evidence for this. She tested her for numerous other conditions: celiac disease, lactose intolerance, and chronic infections -- including parasites she could have picked up in China or Haiti -- but every test came back negative. With Mrs. C losing weight and with no end to her diarrhea in sight, Dr. Wolf became increasingly frustrated.
Hormones in the Gut
On a hunch, Dr. Wolf ordered a test of the gastrin level in her blood. The hormone gastrin is a fascinating protein, released by the stomach during a meal to stimulate the production of stomach acid to help digest the food that is on its way down the esophagus. In response to gastrin, we make almost 3 liters of stomach acid per day. That's actually quite a lot of fluid. Mrs. C's gastrin level was abnormally high, meaning she was telling her stomach to make volumes of stomach acid that passed out of her body as diarrhea.
But why was Mrs. C's gastrin level high? Dr. Wolf suspected the Zollinger-Ellison syndrome, a disease that refers to a tumor in the gut that produces abnormally high levels of gastrin. To confirm her thinking, Dr. Wolf administered secretin, another hormone, which would nudge a tumor to make more gastrin. In response to the secretin, Mrs. C's gastrin levels multiplied almost 20 times, confirming that she did indeed have a tumor, hidden somewhere in her gut, that was manufacturing unwanted levels of gastrin.
Life Gets in the Way
Following a series of scans, Mrs. C went to surgery, so doctors could hunt for the hidden cancer. Her surgeon, an expert in cutting out these kinds of cancers, found a mass in the duodenum, the part of the gut that receives food from the stomach. Not only that, the surgeon found the tumor had metastasized to the liver. Dr Wolf was right -- the pathology from the surgery confirmed that Mrs. C had Zollinger-Ellison syndrome.
Since undergoing surgery and starting medications that shrink the tumor, Mrs. C's diarrhea is almost gone. She no longer needs to worry about having accidents. In many ways, she wishes she had been more aggressive about seeking an answer for her symptoms earlier, especially since she knew something was wrong, given her training as a nurse. "But cobblers' kids go barefoot and dentists have all the cavities," she laughs. "This wasn't denial though. This was me coping with my symptoms. My husband never knew what I was going through when we traveled. Later, he said that I was the greatest actress."
Throughout the last decade, Mrs. C wasn't ignoring her problem. In fact, she worked hard to deal with its repercussions. She knew she should have probably seen doctors more persistently. But her symptoms almost became part of her life -- and she was just so busy. "Life kept getting in the way," she muses.
Dr. Wolf agrees. Many patients often have symptoms for a long period of time, and sometimes, such symptoms are almost forgotten even though they present formidable obstacles to daily routine. But in many cases, such symptoms, if addressed early, could be signs of an illness that is curable. Mrs. C, fortunately, knew to visit a doctor when her decade of symptoms became significantly worse. "If something's gone on for a long time -- and then it suddenly changes its character, this is a red flag," Dr. Wolf says.
Now, Mrs. C is back on her feet again. In fact, she has already planned a cruise on the European seas with her husband this summer; she can't wait to set sail.
Do you have your own medical mystery? Send me a description of your own case and I will consider writing about it. E-mail me at firstname.lastname@example.org.