Incidental Finding

An incidental finding is anything a healthcare provider finds on a test that wasn’t what they were originally looking for. In other words, an incidental finding isn’t causing noticeable symptoms. Areas of abnormal tissue — which providers often call “incidentalomas” — are some of the most common incidental findings.

Incidental findings are most commonly found during imaging tests, including:

• X-rays
• CT scans
• MRI
• Ultrasounds
• PET scans

Incidental findings aren’t always something your provider can see. For example, genetic testing also sometimes reveals incidental findings — you might carry a gene mutation that isn’t causing symptoms.

Are incidental findings serious?

Incidental findings on imaging scans are very common. They aren’t often serious. Especially as we get older, it’s normal to have small areas of tissue damage (for instance, from a previous infection) or differences in how our insides look on camera. And devices like CT scanners are becoming more advanced and providing more detailed images. This allows healthcare providers to see even minor differences on imaging. But some incidental findings can mean you have a serious health condition and need immediate treatment.

What are examples of incidental findings?

Examples of incidental findings include:

• Lesions, or areas of abnormal tissue (masses, cysts, tumors or nodules)
• Kidney stones or gallstones
• Hernias
• Granulomas
• Blood clots
• Aneurysms
• Coronary artery calcifications
• Anatomical differences (for instance, duplex kidney or extra lumbar vertebrae)

What are common incidental findings on imaging?

Lesions — areas of abnormal tissue that can be cysts, nodules or tumors — are the most common incidental findings. Providers can find them on imaging of any organ or bone, including chest CTs, brain MRIs and abdominal scans. They often aren’t harmful or cancerous (they’re benign).

Common incidental lesions include:

• Adrenal masses: Adrenal masses are very common and almost always benign. They’re often adrenal adenomas.
• Kidney masses: Providers see renal (kidney) masses on up to 40% of kidney imaging. Most are benign kidney cysts, but you may need additional imaging or testing to be sure.
• Liver nodules: Providers see liver nodules on about 15% of CT scans. Providers estimate that about half of all people have benign liver nodules. You may need more tests to determine whether you need treatment.
• Ovarian cysts: Simple cysts are common and often resolve on their own. Providers look at features of ovarian cysts and note their size and what they look like. They usually monitor or get additional imaging of cysts that are larger but appear benign. Smaller cysts usually don’t need to be monitored.
• Pituitary masses: About up to 1 in 5 people have pituitary masses. They’re often cysts or adenomas.
• Pulmonary nodules: Pulmonary nodules are an incidental finding on about 1 in 3 chest CT scans. Small nodules are usually benign.
• Thyroid nodules: Providers find incidental thyroid nodules on up to 68% of imaging studies. Most are benign.