Glioblastoma multiforme

Question 1

What are the 5 microscopic features of GBM?

Answer 1

1. High cellularity;
2. Cellular and nuclear anaplasia;
3. Mitoses;
4. Microvascular proliferation; and
5. Necrosis.

Question 2

What is a ‘pseudopalisading’ pattern of tumour cell arrangement?

Answer 2

Cells arranged in a perpendicular fashion around serpiginous necrotic areas (proposed that they are migrating away from a central hypoxic area).

Question 3

What is the pattern of thrombosis and microvascular proliferation in GBM?

Answer 3

1. Thrombosed vessels in the central necrotic area;

2. Microvascular proliferation in adjacent areas to sustain tumour growth.

Question 4

What processes are involved in GBM angiogenesis?

Answer 4

1. Tumour outgrows its blood supply, resulting in hypoxia;
2. Upregulation of hypoxia inducible factor 1 (HIF-1);
3. Expression of vascular endothelial growth factor (VEGF).

Question 5

What are the characteristic features of new GBM blood vessels?

Answer 5

1. Arranged in glomeruloid formation;

2. Lack a blood brain barrier.