Incidental finding
What it means
An unexpected abnormality found on an investigation performed for an unrelated reason — the "incidentaloma". As imaging volume and resolution rise, these are increasingly common, and the harm they cause is real: anxiety, further investigation, invasive biopsy and occasionally treatment of something that would never have caused symptoms (overdiagnosis).
Worked example
A CT for suspected renal colic reports a 6 mm pulmonary nodule. The stone passes; the nodule generates two years of surveillance scans and considerable anxiety. Managed by the guideline (British Thoracic Society nodule pathway, stratified by size and risk) that anxiety is bounded and proportionate; managed ad hoc it is not.
In the exam
An investigation ordered for one problem reports an unrelated abnormality, and the patient asks what it means.
What settles it
Three questions, in order: does this finding need action AT ALL (many do not); is there a specific guideline for it (adrenal, pulmonary nodule, renal cyst, pancreatic cyst and thyroid nodule all have one); and would finding disease change what we would actually do for THIS patient, given their age, comorbidity and wishes? Tell the patient regardless — non-disclosure is not an option — but frame the risk honestly rather than defensively.
Classically confused with
A finding that explains the presenting problem
Source: Royal College of Radiologists · British Thoracic Society pulmonary nodule guideline · GMC decision-making and consent guidance