Knowing When to Respond to Incidental Findings

This is the third in a series of articles about radiologists’ role in the identification and communication of incidental findings. Read the first and second articles in the series.

Incidentalomas—unexpected, abnormal findings—occur in 20% to 40% of all advanced imaging studies, according to Matthew Davenport, MD, MBA, the William Martel Professor of Radiology and professor of urology at Michigan Medicine in Ann Arbor. In an American Journal of Roentgenology article, Dr. Davenport noted that incidental findings often lead to low-value care.

“Some cancers are indolent and may never hurt a patient if they had never been detected,” Dr. Davenport said.

Identifying such indolent cancers and treating them early often contributes to patient harms without improving patient care, he noted. 

“Highly-aggressive, lethal cancers usually warrant treatment when found—but it’s rare for them to be discovered incidentally in patients who don’t already show symptoms,” Dr. Davenport said.

Finally, some cancers fall in the middle: they have the potential to harm, but they are not as fast growing as highly aggressive types. Dr. Davenport asserted that these cancers are most suited to early detection and treatment using typical imaging methods.

When Context Shapes Importance

Many patients and providers have different feelings about the potential benefits of addressing incidentilomas compared to the potential harms of test anxiety, unnecessary costs and complications from unnecessary complications. Grappling with these complexities is challenging.

According to Dr. Davenport, the importance of an incidental finding depends a lot on the patient’s other health risks. “For example, if a scan picks up a small pulmonary nodule, it is often benign,” he said. “However, if the patient is a smoker, which is a major risk factor for lung cancer, the risk of the finding goes up, and our approach to it changes. Risk factors have a large role in determining the importance of an incidental finding.”

Many guidelines describing the management of incidental findings are overly weighted toward missing a potential cancer, with less regard given to whether identification improves health, Dr. Davenport noted. “This focus on sensitivity rather than the complications of overdiagnosis and overtreatment fuels the population-level harm and economic loss resulting from over-pursuit of incidental findings that have repeatedly been shown in large studies of incidental findings management,” he said. 

Many abdominal incidentalomas will only harm the patient if the radiologist’s response leads to an unnecessary series of workups, according to Perry J. Pickhardt, MD, John R. Cameron Professor of Radiology and Medical Physics and chief of gastrointestinal imaging at the University of Wisconsin, Madison.

In a British Journal of Radiology commentary, Dr. Pickhardt emphasized that these workups can cause patient anxiety as well as unnecessary costs and complications. He also noted that it’s important not to confuse imaging-based incidentalomas with the practice of opportunistic screening.

“They are quite different,” Dr. Pickhardt said. “Incidental findings often carry a more negative connotation and require radiologists to responsibly handle unsuspected imaging findings while being careful not to trigger unnecessary additional workups.”

“On the other hand, opportunistic screening implies leveraging useful imaging data, such as tissue and organ measures present in all patients,” he continued. “For example, routine body CT is an ideal high-volume modality for quantitative assessment of tissue composition that can assist with cardiometabolic risk stratification and identification of presymptomatic conditions like osteoporosis or heart disease.”