Histopathology - Brain

Question 1

Answer 1

Liquefactive Necrosis

 Structure in center disappears, less eosinophilic

 White spaces indicate spongiosis (intercellular) edema

 Nuclei of dying neurons disappear

 Aka “infarction” because of blockage to cerebral artery

 Normally, brain has no neutrophils, macrophages, or fibroblasts. When the BBB is damaged

in infarct, macrophages enter brain tissue

o Appear foamy because of their triglycerol and cholesterol content o Hemosiderin
o Neutrophils not characteristic

 In early stage of ischemia, neurons swell and become ‘red giant’ neurons. More sensitive to hypoxia than astrocytes

Question 2

Answer 2

Purulent Meningitis

 Many granulocytes

 Usually, meninges should not be seen, but here they are visible

 Dilated vessels

 Pus consists of polymorphonuclear cells (=neutrophil granulocytes) in subarachnoid space

 Pus has entered into the meninx. Can be a consequence of pneumonia, tumor, or other

infections.

Question 3

Answer 3

Meningioma

 Meningiomas may be on the meninx, or they may be extrameningial (usually near choroid plexus of ventricles) or extracranial

 Mostly benign, but can cause pain and focal epilepsy

 Spindle cell arrangement forms fascicles. Depending on the section, they may look appear

long, or small, round cross-sections

 No normal tissue seen here

 Often have progesterone receptors, and grow faster during pregnancy

Question 4

Answer 4

Schwannoma