A 34-year-old HIV-positive woman (CD4 count 55 cells/uL) presents with 10 days of headache and right-sided weakness. MRI brain shows multiple ring-enhancing lesions with marked perilesional oedema involving the basal ganglia. Serum Toxoplasma gondii IgG is positive. She is haemodynamically stable. What is the best next step?
- A Stereotactic brain biopsy
- B Empirical pyrimethamine, sulfadiazine and leucovorin ✓
- C Whole-brain radiotherapy
- D Intravenous acyclovir
Correct answer: B. Empirical pyrimethamine, sulfadiazine and leucovorin
Explanation
Multiple ring-enhancing lesions in the basal ganglia with positive Toxoplasma IgG in a patient with CD4 under 100 cells/uL allow empirical anti-toxoplasma therapy without biopsy. Clinical and radiological improvement within 2 weeks confirms the diagnosis. Biopsy is reserved for non-responders or IgG-negative patients. The main mimic, primary CNS lymphoma, is typically solitary, homogeneously enhancing and associated with Epstein-Barr virus DNA in CSF.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.