Incidental findings and overdiagnosis in children — formative SAQs

SAQ 1 — Trauma CT incidental finding (10 marks)

A previously well 9-year-old has CT after significant blunt abdominal trauma. The scan answers the trauma question. It also reports a small simple renal cyst. The child is now comfortable, eating and haemodynamically stable. Parents are frightened by the word “cyst.” [7] [4]

Questions

1. Define incidental finding and overdiagnosis, and state how they differ from underdiagnosis. (3 marks) [2] [3] [1]
2. Classify this cyst using an act / plan / observe / stop framework and justify. (3 marks) [4] [7] [6]
3. Outline the family explanation and handover content, including residual risk. (4 marks) [4] [1] [10]

Model answer

Definitions (3). Incidental finding: unexpected result unrelated to the clinical question that prompted the test. Overdiagnosis: detection of a condition that would not have caused harm, yet still leads to a disease label, further tests or treatment. Underdiagnosis: missing disease that is present and matters. These are not interchangeable. [2] [3] [1]

Classification (3). Most simple renal cysts in a now-stable child after the trauma question is answered sit in planned follow-up or observe rather than act-now. Justify with clinical stability, likely benign morphology as reported, and avoidance of same-night cascade imaging. Escalate bin if report features are suspicious or the child is unwell. Document local radiology follow-up advice. [7] [4] [6]

Communication and handover (4). Explain: the scan answered the injury question; the cyst was an extra finding; it is not the cause of the injury; most such cysts are monitored rather than operated on urgently; return if pain, fever, haematuria or systemic change. Handover: original trauma status, incidental description, bin chosen, follow-up owner/timing, residual trauma and medical risks still open. Do not copy the cyst into the problem list as cancer. [4] [1] [10]

SAQ 2 — Continuous oximetry cascade in bronchiolitis (10 marks)

A 5-month-old with typical bronchiolitis is improving: feeding, interactive, mild residual wheeze. Continuous pulse oximetry shows brief self-resolving desaturations during sleep. A night registrar wants chest radiograph, blood gas and high-flow “because the monitor keeps alarming.” Parents are not sleeping. [5] [9] [8]

Questions

1. Explain how technology can create overdiagnosis in this setting. (3 marks) [5] [1]
2. State which further tests are low value here and when imaging would become reasonable. (3 marks) [8] [6]
3. Give a stepwise plan that protects the child and the family without under-calling deterioration. (4 marks) [5] [9] [6]

Model answer

Technology and overdiagnosis (3). Continuous oximetry detects brief desaturations that may not represent new disease needing escalation. Labelling these as hypoxaemic respiratory failure can drive oxygen, investigations and prolonged stay — overdiagnosis and cascade effects. Parental anxiety rises with monitor focus. [5] [1] [9]

Low-value tests and imaging threshold (3). In classic improving bronchiolitis, routine chest radiograph has low utility and can generate incidental opacities that prompt antibiotics. Blood gas and high-flow are not mandated by isolated sleep desaturations in a well-appearing infant. Imaging becomes more reasonable if course is atypical: focal findings, marked asymmetry, high fever trajectory, suspected complication or true increased work of breathing. [8] [6] [5]

Stepwise plan (4). Reassess the child off the chart: work of breathing, feeding, interaction. Treat the child, not every blip. Step down continuous monitoring when clinically appropriate; consider spot checks. Explain to parents why alarms can mislead and what true warning signs are. Safety-net and senior review if physiology worsens. Document residual risk of evolving lower respiratory disease without inventing a new diagnosis from the monitor alone. [5] [9] [6]