Sunday, November 2, 2014

A 37-year-old woman with a history of 6 months

A 37-year-old woman with a history of 6 months
of worsening headache is admitted to the hospital after a tonic-clonic seizure that occurred at work. The seizure lasted a short time and terminated spontaneously.

On examination her vital signs are normal, she is somnolent but awake, and there are no focal abnormalities. Her initial CT scan showed no acute hemorrhage but was abnormal. An MRI is obtained and is shown in Figure .

What is the most likely diagnosis in this patient?

A. Brain abscess
B. Glioblastoma
C. Low-grade astrocytoma
D. Meningioma
E. Oligodendroglioma

The answer is D. (Chap. 379) The postgadolinium MRI shows multiple meningiomas
along the falx and left parietal cortex. Meningiomas derive from the cells that give rise
to the arachnoid granulations. They are now the most common primary brain tumor,
accounting for approximately 32% of the total, and occur more commonly in women than
men. They are usually benign (WHO classification grade 1) and attached to the dura.

They rarely invade the brain. Meningiomas are diagnosed with increasing frequency as more
people undergo neuroimaging studies for various indications. Their incidence increases
with age, and they are more common in patients with a history of cranial irradiation.

They are most commonly located over the cerebral convexities, especially adjacent to the
sagittal sinus, but can also occur in the skull base and along the dorsum of the spinal cord.
Many meningiomas are found incidentally following neuroimaging for unrelated reasons.

They can also present with headaches, seizures, or focal neurologic deficits. On imaging
studies they have a characteristic appearance usually consisting of a partially calcified,
densely enhancing extra-axial tumor arising from the dura. The main differential diagnosis
of meningioma is a dural metastasis. Total surgical resection of a meningioma is curative.

Low-grade astrocytoma and high-grade astrocytoma (glioblastoma) often infiltrate
into adjacent brain and rarely have the clear margins seen in Figure . Oligodendroma
comprise approximately 15% of all gliomas and show calcification in roughly 30%
of cases. They have a more benign course and are more responsive than other gliomas to
cytotoxic therapy.

For low-grade oligodendromas, the median survival is 7–8 years. Brain
abscess will have distinctive ring-enhancing features with a capsule, will often have mass
effect, and will have evidence of inflammation on MRI scanning.

  • --DrSudeepKC


Post a Comment