GLIOBLASTOMA

GLIOBLASTOMA 
  • Glioblastoma is highly malignant glial tumor that arises either denovo or  from pre-existing anaplastic / diffuse astrocytoma (secondary glioblastoma).
  • Glioblastoma is WHO grade IV tumor
Clinical features
  • Commonly affects cerebral hemispheres in adults and brain stem and thalami in children
  • Most of them occur as solitary but multicentric glioblastomas can also occur
  • Patients present with frank neurologic deficit or with signs of increased intracranial pressure.
  • Tumor grows fastly with in weeks to months to large contrast enhancing mass.
Radiologic features 
  • MRI shows “ring” or “rim” of contrast enhancement that circumscribes a dark areas of necrosis in post contrast T1-weighted images
  • General broad zone of surrounding edema is evident in T2 weighted images
  • An unusual variant Giant cell Glioblastoma lacks the central core of necrosis which is typical for Glioblastoma.
Gross 
  • Tumor is gray-white fleshy with central necrotic core.
  • Glioblastoma is usually diffuse and infiltrating except giant cell type which is very well circumscribed.
  • Surface shows thrombosed vessels which are distinctive.
Microscopic features
  • Glioblastoma shows the features of astrocytoma with areas of necrosis, vascular proliferation and high mitotic count.
  • Necrosis takes the form of either large confluent areas or small often multiple serpiginous foci. Necrotic areas are often surrounded by peripheral accumulation of some what radially oriented cell (pseudopalisading).
  • Vascular proliferation is present which can be in two forms
    • Glomeruloid vascular proliferation –  globular masses resembling the glomerular tufts of kidney            which exhibits directional growth towards zone of necrosis. In this smooth muscle and pericytes         also proliferate
    • Second form is endothelial proliferation which is intraluminal with in small and medium sized                vessels. Thus there is single lumen which may be obliterated by proliferating endothelial cells
  • Microvascularity of glomeruloid type are associated with low grade glioma where as endothelial proliferation is associated with high grade glioma.
  • Perivascular arrangement of tumor cells resembling pseudorosettes of ependymoma can also occur
  • if the tumor has predominantly giant cells, then it is termed as “Giant cell glioblastoma”
  • other patterns which can be seen are adenoid, papillary formations and squamous pearls.
  • Other metaplastic tissue which can be seen in glioblastoma include bone, cartilage or skeletal muscle.
Immunohistochemistry
  • The tumor cells are positive for GFAP and also for s-100 and vimentin.

 

GBM 1

Glioblastoma: Tumor showing increased cellularity and nuclear pleomorphism (H&E,X100)

GBM 2

Glioblastoma: Tumor with extensive areas of necrosis (right side) (H&E,X100)

 

GBM 3

Glioblastoma: Serpigenous areas of necrosis with pseudopalisading of tumor cells (H&E,X400)

 

glioblastoma 4

Glioblastoma: Serpiginous areas of necrosis with pseudopalisading tumor cells (H&E,X400)

 

Glioblastoma5

Glioblastoma: Serpigenous areas of necrosis with pseudopalisading of tumor cells (H&E,X400)

 

Glioblastoma 6

Glioblastoma: Serpigenous areas of necrosis with pseudopalisading of tumor cells (H&E,X100)

 

Glioblastoma 7

Glioblastoma: Vascular proliferation forming glomeruloid like structures (H&E,X100)

 

Glioblastoma 8

Glioblastoma: Tumor cells forming perivascular rosettes (H&E,X100)

 

Glioblastoma 9

Glioblastoma: Tumor cells forming perivascular rosettes (H&E,X100)

 

Glioblastoma 10

Glioblastoma: Oligodendrglial like cells (H&E,X400)

 

Glioblastoma 11

Glioblastoma: Tumor shows mucinous areas with cords of tumor cells and necrotic foci (H&E,X400)

 

Glioblastoma 12

Glioblastoma: Tumor cells having clear cytoplasm (H&E,X400)

 

Glioblastoma 13

Glioblastoma: Tumor with gemistocyte like cells (H&E,X100)

 

Glioblastoma 14

Glioblastoma: Tumor with squamous metaplasia (H&E,X400)

 

Glioblastoma 15

Glioblastoma: Periphery of the tumor showing vessels with thrombi – distinctive feature of GBM (H&E,X100)

 

Glioblastoma 16

Glioblastoma: Periphery of the tumor showing vessels with thrombi – distinctive feature of GBM (H&E,X100)