The widespread use of cross‐sectional imaging (CT, MRI, ultrasound) means that more and more people are being told they have an unexpected finding, a so‑called incidentaloma. In many cases these are benign, but in others they may represent early disease that warrants monitoring or treatment. Proper characterization is critical and a second opinion from a radiologist specializing in body imaging can make all the difference.
For patients who have been told they have a “lesion” in the liver or kidney and are left feeling uncertain, this article explains: what these findings often represent, how frequently they are misinterpreted (or under‑characterized), why specialization matters, and how you can use MDView to get clarity.
What Are Incidental Liver And Kidney Lesions?
- - Incidental liver lesions are focal abnormalities seen on imaging of the abdomen when the exam was performed for another reason (e.g., abdominal pain, trauma, routine screening). Many are benign (such as simple cysts or hemangiomas), but small or atypical lesions can require further evaluation.
- - Incidental kidney lesions similarly refer to masses or cysts found on imaging done for unrelated reasons. Some are benign (simple cysts), but others may be complex and carry a risk of malignancy.
As these findings were not the primary focus of the imaging study, the exact nature of such lesions may not always be well defined in the initial report. That’s where second‐opinion review by a specialist can add value.
How Frequently Are These Found and What Are the Risks?
In a review of incidental focal liver lesions in otherwise healthy subjects, a study noted that with increased use of multi‑detector CT, tiny hepatic lesions (“too small to characterize” or TSTC) are frequently depicted. For example, in one older study, TSTC lesions were found in 17% of patients undergoing abdominal CT (17% in patients without known malignancy) but were benign in 100% of those without known malignancy.
- For incidental renal masses found on unenhanced CT, one study (O’Connor et al., 2011) showed that such masses occur with non‐negligible frequency and the clinical relevance varies.
- A recent review in the Australian Journal of General Practice reported that incidental renal and adrenal masses account for ~14% of incidentalomas on CT scans.
- With liver incidentalomas, one symposium commentary noted that although “most turn out to be benign,” the finding of an incidental liver lesion becomes a source of anxiety and prompts further imaging.
These numbers show that incidental lesions are common and while many are benign, the key challenges are: (1) distinguishing benign from potentially malignant or clinically significant lesions, and (2) avoiding unnecessary follow‐up/biopsy for truly benign lesions.
Why Misdiagnosis or Under‑Characterization Happens
There are multiple reasons why incidental lesions may be mis‑characterized or incompletely assessed:
-
- The initial radiologist may be a generalist rather than a board‐certified subspecialist in body imaging. Subspecialty radiologists (liver/kidney imaging experts) have deeper familiarity with variant appearances of benign vs malignant lesions.
- The lesion may be small, in a difficult location, or have atypical imaging features (making classification challenging). For example, “too small to characterize” (TSTC) lesions in the liver. - - Imaging protocol may not have included the ideal phases or sequences (e.g., multiphase contrast for liver, or MRI for renal cyst characterization). For example, for incidental liver lesions: multiphase contrast CT has 91%–95% accuracy for diagnosing hemangioma, 85%–93% for focal nodular hyperplasia (FNH), and 96%–99% for hepatocellular carcinoma (HCC) in appropriate settings.
- - The reporting language may be vague (“indeterminate lesion, follow‐up recommended”) rather than definitive. This can cause confusion for patients and physicians.
- - Clinical context is sometimes missing (e.g., the patient’s history of malignancy, liver disease, or risk factors), which affects the probability of malignancy and the appropriate work‑up pathway.
A second opinion by a subspecialist radiologist can improve clarity, reduce uncertainty, and potentially avoid unnecessary tests or interventions.
What Studies Show About Outcomes and Why Specialization Matters
- A systematic review on incidental findings in healthy subjects noted that incidental focal liver lesions are “frequent” and called for clear categorization by radiologists.
- In “Imaging and Management of Incidental Renal Lesions” (Mazziotti et al., 2017), the authors provide guidance on how to recognize and classify incidental renal findings and emphasize the importance of assessing risk of malignancy in solid and cystic lesions.
- In “Incompletely Characterized Incidental Renal Masses” (Silverman et al., 2015), focus is given to the cost‐effectiveness and diagnostic challenges of indeterminate renal masses and the value of imaging strategies.
- In “Incidentally Detected Focal Liver Lesions” (Semaan et al., 2016), the authors recommend further cross‐sectional imaging if the lesion is under 1 cm or the quality of imaging is low.
- The American College of Radiology (ACR) has published appropriateness criteria and white papers for managing incidental liver lesions on CT, noting accuracy values of various imaging strategies.
Putting all of these studies together, the general consensus is that a non‐trivial proportion of incidental lesions may require follow‐up or intervention (though the vast majority may end up benign). Also, imaging characterization is improved when subspecialty protocols and expertise are used and clear communication about significance and next steps is important for patient care
When You Should Consider a Second Opinion
Here are some red flags/situations in which seeking a second opinion makes sense:
- - Your report notes an “indeterminate” or “unclear” lesion (in liver or kidney) and recommends “follow‑up” but you’re left wondering what that means.
- - A lesion was discovered and surgery, biopsy or invasive intervention is being recommended before it has been clearly characterized by a subspecialist.
- - You have persistent symptoms (pain, discomfort, abnormal labs) that don’t match the imaging conclusion (e.g., lesion deemed benign but symptoms persist).
- - You have a known risk factor (e.g., prior malignancy, liver disease, kidney disease) and the imaging report doesn’t seem to integrate that context fully.
- - You simply want clarity: a second opinion can provide a plain‑language explanation of what the lesion likely is, what monitoring (if any) is needed, and what to ask your referring physician.
How MDView Can Help You
At MDView, you get:
- - Access to board‑certified radiologists specializing in body imaging (liver/kidney)
- - A second opinion review of your imaging exam (CT, MRI, ultrasound) within 72 hours or less
- - A detailed report done by an expert, and the ability to use the platform's AI Insights tool to get a thorough explaining in plain language explaining what was found, what it means, and next‑step options
- - Reduced anxiety, better informed decisions, and potential avoidance of unnecessary procedures
For example: if your abdominal imaging showed a small kidney lesion but the report said “likely benign, consider follow‐up,” you can share this information with the radiologist via the MDView questionnaire and they can review the images, apply the appropriate classification, and advise whether surveillance, further imaging, or referral is appropriate.
Likewise, for incidental liver lesions, if your report noted a “small lesion, too small to characterize,” you can share this information with the specialist so they can assess whether the imaging protocol was adequate, whether additional sequences or MRI might clarify, and whether this actually merits follow‑up.
Request a Radiology Second Opinion Today
If you’ve had an imaging exam (CT, MRI or ultrasound) that discovered a liver or kidney lesion and you’re unsure what it means, don’t wait. Submit your scans to MDView for a rapid, expert second opinion from a body imaging radiologist. Get clarity, avoid unnecessary procedures, and sleep better at night knowing exactly what the images show.
To get started, upload your exam to https://app.mdview.com. If you don't have access to your exams, the MDView team can get them on your behalf at no cost to you! Just click Have MDView Get My Exam to get started.