Differential Diagnosis for a 5-year-old boy with Tetralogy of Fallot
Single most likely diagnosis
- B) Brain abscess: The presence of a ring-enhancing lesion in the right cerebral hemisphere, along with symptoms such as headache, lethargy, irritability, and seizures, is highly suggestive of a brain abscess. Tetralogy of Fallot, a congenital heart defect, increases the risk of brain abscess due to the potential for paradoxical emboli or seeding of bacteria from the bloodstream.
Other Likely diagnoses
- A) Arteriovenous malformation (AVM): Although less likely than a brain abscess, an AVM could present with seizures and a mass effect. However, AVMs typically do not present as ring-enhancing lesions on CT scans.
- E) Rupture of a cerebral artery aneurysm: This could cause sudden onset of symptoms, but it's less common in children and might not typically present as a ring-enhancing lesion.
Do Not Miss diagnoses
- E) Rupture of a cerebral artery aneurysm: Although less likely, missing a ruptured aneurysm could be catastrophic due to the high risk of rebleeding and severe neurological consequences.
- A) Arteriovenous malformation (AVM): Similar to an aneurysm, missing an AVM could lead to severe outcomes if it ruptures.
Rare diagnoses
- C) Frontal lobe meningioma: Meningiomas are rare in children and would be an unusual cause of these symptoms.
- D) Lacunar infarct: Lacunar strokes are more common in adults with hypertension and diabetes, making this a rare consideration in a child.
- F) Temporal lobe astrocytoma: While brain tumors can present with seizures and mass effect, the specific imaging findings and clinical context make this a less likely diagnosis compared to a brain abscess.