Incidental findings and overdiagnosis in children — branching viva

Station opening

Examiner: Define overdiagnosis in one sentence a parent could understand, then distinguish it from a false-positive test and from underdiagnosis. [1]

Strong candidate: [1]

• Overdiagnosis means we found something that looks like a disease label, but it would not have harmed the child if we had never looked — and the label still leads to more tests or treatment. [2] [1]
• A false positive is a wrong abnormal result (contamination, wrong range). Overdiagnosis can involve a “true” abnormality that still never would have mattered. [2]
• Underdiagnosis is missing disease that is present and matters. Restraint is not an excuse to underdiagnose. [3]

Branch A — Trauma CT incidental

Examiner: CT after trauma is clear for injury. Report also notes a small simple renal cyst. Child is well. Parents are distressed. What do you do next? [1]

Must hit: [7] [1]

1. Restate the original clinical question and confirm trauma pathway status. [7]
2. Bedside reassess the child before cascading. [1]
3. Sort into act / plan / observe / stop with justification. [4] [6]
4. Explain cascade risk if every incidental is chased same night. [9] [4]
5. Name residual risks still open (missed injury evolution, rare significant lesion if morphology uncertain). [7] [3]

Stretch: Outline handover with owner and timed follow-up rather than problem-list cancer labels. [4]

Branch B — Monitor alarms

Examiner: Recovering bronchiolitis infant; brief sleep desaturations on continuous oximetry; registrar wants radiograph, gas and high-flow. [1]

Must hit: [5] [1]

1. Technology can create uncertainty and overdiagnosis of hypoxaemia. [5]
2. Examine work of breathing, feeding and interaction — treat the child. [5] [1]
3. Routine radiography in classic bronchiolitis has low utility and can generate incidental opacities. [8]
4. Step-down monitoring plan and parental explanation of alarms. [5]
5. State what would change your mind (true increased work, poor feeding, focal findings, atypical fever trajectory). [6] [10]

Branch C — Maximal testing demand

Examiner: Well child after viral illness. Family wants every blood test listed online for rare diseases. [1]

Must hit: [6] [1]

1. Acknowledge fear without mockery. [6]
2. Explain low pre-test probability and false-alarm/cascade risk of broad panels. [1] [6] [9]
3. Offer focused plan if red flags appear; concrete return triggers. [6]
4. Do not invent certainty; do not flood with unsorted rare lists. [1]
5. Document residual risk and safety net. [3]

Closes and common fails

Fails: treating the report as the patient; equating thoroughness with safety; using “avoid overdiagnosis” to dismiss caregiver concern or evolving physiology; ownerless handovers; mandatory radiograph for every oximetry blip. [1]

Distinction: links definitions to Newman-Toker/Brodersen/Coon cleanly; uses four-bin classification fluently; names cascade literature; balances stewardship with must-not-miss residual risk. [1] [2] [3] [4]