CNS toxoplasmosis in HIV vs Primary CNS lymphoma in HIV
How to tell CNS toxoplasmosis in HIV and Primary CNS lymphoma in HIV apart when a board question makes them look alike.
Toxo is usually multiple basal ganglia ring lesions with positive IgG and treatment response; CNS lymphoma is often solitary/periventricular EBV-associated mass.
Side by side
CNS toxoplasmosis in AIDS causes fever, headache, seizures, focal deficits, positive Toxoplasma IgG, and multiple ring-enhancing lesions often in basal ganglia.
Primary CNS lymphoma in AIDS is EBV-associated B-cell lymphoma that often presents with solitary or periventricular enhancing mass lesions and may show EBV DNA in CSF.
Latent Toxoplasma gondii tissue cysts reactivate when cellular immunity falls, causing necrotizing abscesses.
Profound immunosuppression permits EBV-driven malignant B-cell proliferation in the CNS.
Multiple ring-enhancing lesions, basal ganglia involvement, positive toxoplasma serology, and clinical response to pyrimethamine-sulfadiazine support toxoplasmosis.
Solitary lesion, periventricular location, EBV CSF PCR, thallium uptake, and lack of response to toxoplasma therapy support CNS lymphoma.
The trap
Both can ring enhance in AIDS, so number/location, toxo serology, EBV evidence, and response to empiric therapy decide.
Watch it explained
Test it nowThe repair move
For AIDS brain lesions, compare multiple basal ganglia toxo pattern against solitary EBV lymphoma pattern.
Try a free question
CoreA patient with AIDS and CD4 count 60 has headache, seizure, focal weakness, positive Toxoplasma IgG, and multiple ring-enhancing basal ganglia lesions. Which diagnosis is most likely?
Show answer and explanation
Answer: A. CNS toxoplasmosis. Advanced HIV with positive Toxoplasma IgG and multiple basal ganglia ring-enhancing lesions supports CNS toxoplasmosis.
Why the other choices are tempting
- B. Primary CNS lymphoma is EBV-associated and often solitary/periventricular.
- C. PML causes nonenhancing white-matter lesions from JC virus.
- D. HSV encephalitis often targets temporal lobes.
- E. Neurosyphilis does not classically cause multiple basal ganglia ring lesions.
Flashcards
Tap a card to flip it.
What imaging pattern supports CNS toxoplasmosis in AIDS?
Multiple ring-enhancing lesions, often in basal ganglia, support CNS toxoplasmosis.
What serology supports toxoplasma reactivation?
Positive Toxoplasma IgG supports prior infection that can reactivate in AIDS.
Quick answers
What is the fastest way to tell CNS toxoplasmosis in HIV from Primary CNS lymphoma in HIV?
Toxo is usually multiple basal ganglia ring lesions with positive IgG and treatment response; CNS lymphoma is often solitary/periventricular EBV-associated mass.
What is the key clue for CNS toxoplasmosis in HIV?
CNS toxoplasmosis in AIDS causes fever, headache, seizures, focal deficits, positive Toxoplasma IgG, and multiple ring-enhancing lesions often in basal ganglia.
What is the key clue for Primary CNS lymphoma in HIV?
Primary CNS lymphoma in AIDS is EBV-associated B-cell lymphoma that often presents with solitary or periventricular enhancing mass lesions and may show EBV DNA in CSF.
What is the common trap with CNS toxoplasmosis in HIV vs Primary CNS lymphoma in HIV?
Both can ring enhance in AIDS, so number/location, toxo serology, EBV evidence, and response to empiric therapy decide.