Tuberculous meningitis

This is a high power view of the meninges from a patient who was HIV-positive. Note the numerous pink-staining, acid-fast bacilli (AFBs). The density of Mycobacterium tuberculosis rods is much higher than in non HIV-associated tuberculous meningitis. This reflects the lower immunocompetence in late stage HIV-infected patients. Ziehl-Neelsen (ZN) stain.