Slide 4.Brain abscess, Cerebrum

A. Brief Descriptions

  1. Types:

    • Emboli cerebral abscess from infected foci in body 40%.

    • Direct extension of cerebral abscess from adjacent infected foci.

    • Relate to cerebral trauma, 30%.

    • Idiopathic abscess, 20%.

  2. Stages :

B. Gross Findings

  1. Discrete lesions with central liquefactive necrosis, surrounding by fibrous, collagenized response and edema.

C. Micro Findings

  1. Necrotic, purulent center.

  2. Capsule of granulomatous tissue & fibrosis (capillaries proliferation, infiltration, Gitter cells...).

  3. Surrounding reactive brain with edema & gliosis.
     

D. Others:

  1. Cerebritis: focal inflammation of brain parenchyma.

  2. Myelitis: focal inflammation of spinal cord.

  3. Focal pyogenic cerebritis.

  4. Emboli suppurative encephalitis.

E. Reference

  1. Robbins Pathologic Basis of Disease, 6th ed.  P.349-352.

 

 

Fig. 4-1 (LP)The normal architecture of cerebrum is destructed.

 

 

 

 

Fig. 4-2 (LP)The necrotic area is in the left, the normal cerebral cortex in the right, and a thick fibrous band lined between them.

 

 

 

Fig. 4-3 (LP)The normal cerebral cortex (left) and the fibrous capsule (right) surrounding the necrotic area (not shown here). Note the rather dense and parallel fibrous bundles of the capsule.

 

 

 

Fig. 4-4 (LP)The fibrous capsule. Note the more outside of the capsule (left side in this picture), the more thickening of the fibrous bundles.

 

 

 

Fig. 4-5 (LP)The necrotic center (right) is surrounded by granulation tissue (left). Note foamy histiocytes (Gitter cells) aggregate in the outermost of the necrotic area.

 

  

 

Fig. 4-6 (HP)The necrotic area is composed of cell debris, nuclear dusts, inflammatory cells (most frequently PMNs) and Gitter cells (foamy histiocytes in the CNS).