Fact-sheet: Cryptococcosis


Updated on 08/26/2020 at 2:33 PM

Note : 0/10

View all RADEOS cases associated with this fact-sheet

Definition

Opportunistic infection due to Cryptococcus neoformans, an encapsulated yeast.

It spreads via the airborne route (inhalation) but also hematogenously in immunocompromised patients.

This is a common fungal infection in immunocompromised patients, mainly in HIV-positive individuals.

Clinical features

  • Meningoencephalitis and meningitis.
    Fever, headache, and confusion, seizures, cranial nerve involvement.

Laboratory findings

Cerebrospinal fluid analysis: elevated protein, hypoglycorrhachia, moderate leukocytosis.
India ink test.

CT

Brain CT:

  • Hydrocephalus.

In immunocompetent patients,

  • solitary pulmonary nodule found incidentally.

In immunocompromised patients

  • responsible for mediastinal lymphadenopathy
  • foci of pneumonic consolidation
  • nodules
  • miliary opacities
  • diffuse interstitial lung disease, bronchopneumonia, and pleural effusions.

MRI

  • Basal meningitis associated with confluent cystic dilatation of the perivascular Virchow-Robin spaces.
  • Involvement of the putaminocaudate regions.
  • Communicating hydrocephalus
  • Gelatinous pseudocyst: T1 hypointense, T2 hyperintense, with minimal surrounding edema, without enhancement following gadolinium injection.
    On T2-FLAIR, these lesions are hyperintense.
  • Cerebral cryptococcomas: T2 hyperintense, surrounded by FLAIR-hyperintense edema, increased ADC.
    Ring enhancement may be seen.
  • Diffusion: decreased ADC due to the viscosity of the content.
  • Spectroscopy: decreased NAA peak, increased choline peak, presence of lipids and occasionally lactate.

Management

Antifungal treatment (amphotericin, fluconazole, therapeutic lumbar puncture)

Differential diagnosis

  • Neuromeningeal tuberculosis
  • Stenosis of the intracranial arteries.
  • Multiple parenchymal cysts.