Glioblastoma multiforme masquerading as pseudotumor cerebri. Case report.

A 16-year-old girl developed headaches and bilateral papilledema while taking minocycline for acne. The initial neuro-ophthalmologic evaluation was normal except for enlarged blind spots OU. An MRI scan demonstrated subtle abnormalities. A lumbar puncture was entirely normal except for an increased opening pressure. A tentative diagnosis of pseudotumor cerebri was made and the patient was treated with Diamox. A second MRI was unchanged, and a lumbar puncture performed while the patient was taking Diamox was entirely normal. The patient subsequently lost vision in both eyes, and a third MRI now revealed a supracellar enhancing mass. Biopsy and subtotal resection of the mass showed it to be a glioblastoma multiforme. This case emphasizes pitfalls in the diagnosis of pseudotumor cerebri. Careful follow-up and a high index of suspicion in pseudotumor cerebri syndromes are essential.