Malakoplakia of the brain. A report of two cases occurring in childhood

Area of Science:

• Neuropathology
• Pediatric Infectious Diseases
• Histopathology

Background:

• Malakoplakia is a rare inflammatory condition, typically affecting the urinary tract in adults.
• Cerebral malakoplakia is exceptionally rare, with only a few pediatric cases reported previously.
• Previous cases of cerebral malakoplakia have been associated with neonatal herpes simplex virus infections.

Observation:

• Malakoplakia was diagnosed in brain biopsy specimens from two children presenting with meningoencephalitis.
• Histological examination revealed extensive brain tissue destruction, cellular infiltration, von Hansemann histiocytes, and Michaelis-Gutmann bodies.
• Ultrastructural analysis confirmed Michaelis-Gutmann bodies with characteristic dense cores and concentric rings, alongside large intracytoplasmic phagolysosomes.

Findings:

• The presence of malakoplakia in these cases, associated with herpes simplex meningoencephalitis, is a significant neuropathological finding.
• The histological and ultrastructural features of malakoplakia were consistent with established diagnostic criteria.
• The co-occurrence of malakoplakia and herpes simplex virus in the central nervous system was observed.

Implications:

• These findings suggest a potential etiological role for viruses, specifically herpes simplex virus, in the pathogenesis of cerebral malakoplakia.
• This challenges the prevailing hypothesis that bacterial agents are the primary cause of malakoplakia, particularly in the context of central nervous system involvement.
• Further research is warranted to elucidate the complex interplay between viral infections and the histiocytic response in malakoplakia development.