A young obese patient on isotretinoin presents with papilledema; which diagnosis is most likely?

• A. Pseudotumor cerebri
• B. Brain tumor
• C. Migraine
• D. Meningitis

Answer: (A)

Papilledema with a young, obese patient who is taking isotretinoin points most toward idiopathic intracranial hypertension (pseudotumor cerebri). This condition is a syndrome of increased intracranial pressure without a mass lesion or hydrocephalus, and it classically affects young, overweight individuals, with isotretinoin use being a known risk factor. The hallmark is optic disc edema (papilledema) from the elevated pressure, leading to headaches and potential transient visual obscurations.

In practice, diagnosis is supported by signs of raised intracranial pressure such as headaches and papilledema, a normal brain MRI or CT without a mass, and an elevated opening pressure on lumbar puncture with normal CSF composition. Management centers on reducing intracranial pressure and addressing modifiable risk factors—weight loss and agents like acetazolamide—while avoiding further retinal or optic nerve damage; optic nerve procedures are considered if vision worsens.

This fits best over the other possibilities: a brain tumor could cause papilledema but would more likely present with focal neurologic signs or imaging evidence of a mass; meningitis would come with fever, meningismus, and CSF abnormalities; migraine can produce visual disturbances but not true papilledema from sustained raised pressure.