Chronic meningitis, hydrocephalus and spinal paraplegia in non-systemic histoplasmosis

Meningite crônica, hidrocefalia e paraplegia medular em histoplasmose não-sistêmica

A 27-year-old immunocompetent agricultural worker presented chronic meningitis and hydrocephalus. Despite CSF and systemic investigation no etiology was defined. Spastic paraplegia installed 15 years later. Spinal and brain MRI are displayed in Figures 1 and 2. The patient developed intracranial hypertension and died days later. A diagnosis of histoplasmosis was made at autopsy (Figure 3).

Figure 1
Thoracic spine MRI. A) Sagittal T2 weighted image showing a low signal central lesion in the spinal cord at T7 level, with associated edema above and below. Sagittal T1 weighted images before (B) and after contrast administration (C) and axial after contrast (D) demonstrate its nodular enhancement.

Figure 2
Brain MRI. A and B) axial T2 weighted images demonstrate low signal lesion located at the anterior horn of the right lateral ventricle (arrow) and another isointense lesion located at the right foramen of Monroe, which suggested the possibility of a granulomatous process. Axial T1 weighted images before (C) and after contrast administration (D) demonstrate its nodular enhancement.

Figure 3
A) Coronal section through brain showing hemorrhagic lesion distending the third ventricle. There is also dilatation of lateral ventricles by blood clots. B) Small subependymal lesion in anterior horn of right lateral ventricle with central caseous necrosis surrounded by thick fibrous capsule and lymphocytic infiltrate. This may have been the entry site for histoplasmas in the brain (primary histoplasmoma). HE, X 40. C) Macrophage in the third ventricle lesion containing abundant microorganisms with features of Histoplasma sp. HE, X 400. D) Small artery in third ventricle wall surrounded and delaminated by parasite filled macrophages. Vasculitis may have caused intraventricular hemorrhage. HE, X 100. E) Histoplasma sp. in macrophage phagosome as small regular yeast forms. Nearly all parasites were intracellular. Grocott’s methenamine silver, HE counterstain, X 400. F) Ultrastructure of Histoplasma sp. in a phagocytic cell. Numerous electron dense viable fungi often with a pale vacuole, surrounded by electron lucent capsule. Electron microscopy, X 2500.

Histoplamosis as isolated central nervous system disease is rare, being more common in immunosuppressed patients¹,². As in this case, it can be a challenging diagnosis, and should be considered in any brain or spinal cord lesion with granulomatous pattern.

References

• ¹
  Kauffman CA. Histoplasmosis: a clinical and laboratory update. Clin Microbiol Rev. 2007;20(1):115-32.
• ²
  Gasparetto EL, Carvalho Neto A, Alberton J, Davaus T, Pianovski MAD, Yamauchi E et al. Histoplasmoma como lesão isolada do sistema nervoso central em paciente imunocompetente. Arq Neuropsiquiatr. 2005;63(3A):689-92. doi:10.1590/S0004-282X2005000400027
  » https://doi.org/10.1590/S0004-282X2005000400027

Publication Dates

• Publication in this collection
  June 2016

History

• Received
  02 Oct 2015
• Reviewed
  03 Mar 2016
• Accepted
  28 Mar 2016