Case 007

History/Physical

History/Physical:

68-year-old right-handed male.

Right-sided weakness worse over past month.

The mass is isointense to brain on this unenhanced T1 image (*). The frontal bone cortex is irregular bilaterally (arrows), in keeping with a prior bifrontal craniotomy.

Post-contrast, the mass enhances avidly (*). This is extra-axial. There are pial vessels (arrowheads) between the brain and the mass. There is invasion of the overlying calvarium (arrow).

There is cortex along the interface between brain and mass (arrows), another indication this is extra-axial. The displacement of the brain causes thinning of the cortex. There is encephalomalacia in the right frontal lobe (arrowheads), likely a sequelae from prior surgery.

Diagnosis: Atypical Meningioma

Hypercellular lesion with sheet-like growth of oval cells.

Prominent nucleoli and abundant mitotic activity (>4 mitoses per 10 high power fields, arrows).