21st June 2024

A 45-year-old woman is admitted with a 2-week-history of fever and progressive visual loss

A 45-year-old woman is admitted with a 2-week-history of fever and progressive visual loss. She has a long history of intravenous drug use and has had little prior engagement with health services. Her examination reveals marked cachexia, generalised adenopathy and left-sided homonymous hemianopia. Her baseline investigations are as listed below:

C-reactive protein: 33 mg/L

White cell count: 8×10⁹/L

Lymphocytes 0.03×10⁹/L

HIV point-of-care antibody test: Reactive

MRI of the brain shows a ring enhancing lesion in the right corticomedullary junction.

Which of the following statements is least accurate regarding this case and condition from those listed below?

Select the SINGLE most appropriate explanation for these results from the list below. Select ONE option only.