Meningioma

Question 1

What cells do meningiomas arise from?

Answer 1

Arachnoid cap cells (clustered around dural venous sinuses)

Question 2

Classic effect of meningiomas on adjacent bone

Answer 2

Hyperostosis

Question 3

Do meningiomas calcify?

Answer 3

Yes (sometimes)

Question 4

What percent of meningiomas are benign?

Answer 4

~ 80% (grade 1)

Question 5

Most likely diagnosis

Dural based mass
Heterogenous with lobulated margins
Intra-calvarial expansion and erosion
No adjacent hyperostosis or calcification

Answer 5

Hemangiopericytoma

Question 6

Most common primary tumor of dural based metastatic disease

Answer 6

Breast, prostate and lung

Question 7

Most likely diagnosis

Dural based mass
Located near the foramen magnum
T1 bright, T2 dark
No adjacent hyperostosis or calcification

Answer 7

Melanocytoma (benign)

Melanocytes are clustered throughout the leptomeninges, but have high concentration around the foramen magnum