Toxoplasmosis

Case contributed by Assoc Prof Frank Gaillard

Presentation

Recent immigrant from Africa with new onset of confusion and headaches.

Patient Data

Age: 45 years
Gender: Male
CT

There are four peripherally enhancing masses in the supratentorial brain at the grey-white matter junction. Additional non-enhancing foci of vasogenic edema in the right frontal region. There is marked surrounding vasogenic edema surrounding the peripherally enhancing masses, with marked mass effect and convexity sulcal effacement.

Conclusion: Multiple enhancing masses at the supratentorial grey-white matter junction is concerning for multiple abscesses or metastatic disease.

MRI

Innumerable, irregular, peripherally contrast-enhancing (T1 C+ not shown) lesions are seen in the supra and infratentorial brain, of varying sizes. These are mostly distributed in the basal ganglia and at the grey-white matter junction. Several of lesions have a mural nodule e.g. in the right basal ganglia, and the left frontal lobe lesion has a target-like pattern of enhancement. No convincing central diffusion restriction. Many are however T2 hypointense centrally, and with foci of susceptibility. Extensive surrounding vasogenic edema. No definite leptomeningeal or pachymeningeal thickening/hyperenhancement. No ventricular enlargement or ependymal enhancement to suggest ventriculitis. No subfalcine, uncal or tonsillar herniation. Paranasal sinuses are unremarkable

Conclusion: Innumerable intra-axial lesions. These most likely represent atypical infection (such as toxoplasmosis, fungal or tuberculosis), especially if the patient is immunosuppressed. The alternative diagnosis is multiple metastases. 

Case Discussion

Following admission, the patient was shown to be HIV positive (new diagnosis, CD4+ 0.21 x 109 /L) and went on to have a biopsy.

Histology

Sections show multiple fragments of brain parenchyma showing a heavy perivascular mixed inflammatory cell infiltrate with many foamy macrophages. Foci of necrosis are identified. Bradyzoites and trophozoites of Toxoplasma gondii are identified in one area. No viral cytopathic changes are seen. 

FINAL DIAGNOSIS: toxoplasmosis.

Toxoplasma gondii IgG Ab: Reactive

PCR on barin tissue: positive for toxoplasma DNA

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Case information

rID: 76689
Published: 8th Jun 2020
Last edited: 8th Jun 2020
Inclusion in quiz mode: Included

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