Imagine you are a medical student, volunteering in a research study to help out a friend. The fMRI during a memory test also happens to pick up a life-threatening aneurysm. Instead of starting classes, you are rushed to the OR. The fMRI's “incidental finding” saves your life.
Or, imagine you are a marathon runner who pushes a little too hard, and collapses from dehydration and exhaustion. The ER staff, being thorough, does an MRI, and a brain tumor is "incidentally noted." It's a slow-growing type, the kind that may never be a real risk. But the surgery to remove it surely does pose risk. You and your doctor choose to wait, doing yearly scans to keep an eye on your own personal sword of Damocles. Your life is now haunted by an incidental finding.
Incidental findings are medical results that you weren't looking for. The x-ray done for lower back pain that uncovers a spot on the liver. The urinalysis done to rule out cystitis that reveals trace protein in the urine.
At first blush, these seem like intrinsically good discoveries—potentially serious illnesses that get uncovered early. But plenty of spots on livers and protein deposits in urine are benign, while the tests required to determine that may not be.
Early this year, I wrote an article about one of my patients with chronic abdominal pain who visited the ER of another hospital. The doctors there—who were not familiar with her decade of dyspepsia—ordered a CT scan. Her stomach, gallbladder, intestines and liver were all in pristine condition, but "incidentally noted,"—the report read—"was a 2-centimeter adrenal mass." These adrenalomas are almost always benign, and almost always found only incidentally. They even have their very own appellation—the incidentaloma.
Nevertheless, I felt boxed into a clinical corner, forced to order expensive and complicated tests to rule out the minute chance of malignancy. The arduous process completely overwhelmed and panicked the patient, and we were never able to get to the actual diseases that she already had—diabetes, depression, and arthritis.
Two months later, I found myself in a Washington D.C. conference room, testifying before a razor-sharp committee of academics from law, nursing, medicine, philosophy, ethics, divinity, research, and government. This was a Presidential Commission for the Study of Bioethical Issues panel on incidental findings. The ethical considerations of incidental findings turned out to be much broader and more intriguing than I, as a ordinary primary care doc, had ever imagined.
In clinical medicine, we worry mainly about things that are uncovered when we doctors order tests and find other things—that's what happened to my patient. It turns out that incidental findings are hardly incidental—they turn up in about a third of CT scans. In the case of abdominal CTs for trauma patients, the number of incidental findings can supersede that of trauma findings—and follow-up is notably spotty. In this age of defensive medicine, routine MRIs, and bundled tests, incidental findings are a daily occurrence.
But there are two other areas in which incidental findings are of escalating concern: research trials and direct-to-consumer medical testing.
Biomedical research is critical to the advancement of medicine, and the unsung heroes are the legions of volunteers who submit to all manner of investigation, mainly for the benefit of society, rather than themselves. But these countless lab tests, CT scans, and MRIs done for specific research questions are as prone to incidental findings as tests done in the clinical world, and pose unique ethical dilemmas.
For example, when a CT is ordered in the clinical world—as for my patient—a trained radiologist evaluates every aspect of the CT, no matter what the initial reason for the scan. But in the research world, these CTs might be of a low resolution, designed to focus on the particular research question, and often interpreted by a research scientist trained to examine just that one thing.