LouAnn Bala, MSN, RN, CPHQ, Vice President, Clinical Solutions, Eon
Of the hundreds of thousands of incidental findings identified in radiology reports every year, among the most consequential are those in breast imaging.
Breast tissue is routinely visualized on cross-sectional imaging such as CT chest, PET/CT, cardiac CT, and thoracic MRI. As imaging volumes continue to rise, so does the opportunity to detect unsuspected breast abnormalities. Published literature reports incidental breast lesions in approximately 0.1% to 7.6% of CT scans, depending on patient population and methodology. Importantly, among lesions that are identified and followed-up, reported malignancy rates range widely but can be substantial.
PET/CT findings are particularly noteworthy. Incidental focal FDG uptake in the breast occurs in roughly 0.36% to 1.12% of scans, yet malignancy rates can exceed 30% to 50%. In other words, while uncommon, these signals carry a high pre-test probability of clinically significant disease.
Malignancy rates in incidental breast findings can exceed 30% to 50%
For health systems committed to high reliability, breast incidentals represent both a risk and a powerful opportunity for earlier cancer detection as they can function as an unplanned early detection mechanism — one that operates outside traditional breast screening programs.
The experience of patient narratives consistently reinforce a critical truth: many of those who were identified through incidental findings were asymptomatic and up-to-date on screening. In one widely cited patient story from the University of Kansas Cancer Center, a woman undergoing imaging for a lung concern had an unexpected breast abnormality identified despite prior normal mammograms. She was ultimately diagnosed with stage III breast cancer.
Peer-reviewed case reports echo similar themes. In one example, a patient undergoing PET/CT surveillance for lymphoma had an incidental hypermetabolic breast focus detected. She had no palpable mass on exam, yet further evaluation confirmed invasive ductal carcinoma.
These cases underscore an uncomfortable reality: even well-functioning screening programs cannot capture every cancer. Incidental detection pathways serve as an important secondary safety net — but only if systems are designed to act on the signal.
Despite the clinical importance of these findings, follow-up reliability remains inconsistent across many organizations. The failure modes are rarely due to a single breakdown. Instead, they reflect predictable system gaps.
The first question is ownership: who is responsible for following up on an incidental finding? While the radiologist may document a recommendation, the ordering provider is typically focused on the primary clinical concern. The primary care physician may not be looped in, or may not be clearly identified at all. Given the ambiguity, patients can easily fall through the cracks.
Unstructured reporting further compounds the issue. Incidental breast findings are frequently buried in narrative text rather than specifically called out. This makes keeping track of such findings and generating reliable lists for follow-up challenging. What’s more, not all entities within, affiliated with, a healthcare system use the same EHR, further fragmenting communication.
Competing clinical priorities also play a role. Emergency physicians, hospitalists, cardiologists, and other ordering providers may appropriately prioritize the acute issue that prompted imaging. The incidental breast finding, while important, may be deferred with the assumption that someone else will address it.
Finally, closed-loop tracking gaps remain common. Many health systems lack longitudinal incidental finding programs with automated surveillance, standardized outreach, and real-time adherence monitoring. That means follow-up is heavily dependent on facility resources and individual vigilance — an approach that limits scalability.
Missed or delayed follow-up of incidental breast findings represents a preventable risk. Studies of incidental breast cancers detected on PET/CT have shown that many tumors are small and potentially curable at the time of discovery. Failure to act on these findings can contribute to later-stage diagnoses, more intensive treatment pathways, and worse outcomes further increasing the cost of care.
There are also important regulatory and quality implications. Breast communication and follow-up intersect with MQSA expectations, ACR incidental findings guidance, and cancer program performance metrics. As organizations mature in their safety infrastructure, incidental management is increasingly viewed as part of an enterprise high-reliability strategy rather than a niche radiology concern.
Operationally, the stakes are equally meaningful. Reliable follow-up supports appropriate diagnostic imaging utilization, improves care coordination, and reduces unwarranted variation across facilities. Conversely, unmanaged incidentals contribute to fragmented experiences, and avoidable clinical risk.
Given their potential to improve early detection, incidental breast findings should be viewed as an enterprise workflow challenge rather than an isolated radiology issue.
In an era where imaging continues to expand and patients increasingly expect coordinated care, breast incidental management is no longer optional. It is a quality and patient safety imperative.
