Case 107. Peptostreptococcal brain abscess (79 y-o M)
Biopsy from a cavity-forming cerebrocortical lesion
Key words : Peptostreptococcus, brain abscess, oral flora
The abscess cavity is filled with neutrophils (HE, low power). The causative microbe, Peptostreptococcus sp., is an anerobic normal flora of the oral cavity   Small-sized, Gram-positive cocci are clustered within the abscess cavity (Gram). The cocci are much smaller than Staphylococcus aureus or Streptococcus pyogenes.
Reference case 107A
Another case (56 y-o M) of brain abscess formed in the cerebellum, directly extending from otitis media. The abscess lesion is formed adjacent to the cerebellar cortex (HE). Brain abscess is a serious complication of otitis media.