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Case 364


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Male patient, 20 years old, previously healthy, presented with cough, fever (not measured) and inappetence (loss of 10 kg) for 20 days. Confusion, drowsiness and gait alteration ("pulling the right leg") 4 days ago. Physical examination: oral thrush, altered level of consciousness and focal neurologic deficit, with reduced mobility of the right inferior member. A magnetic resonance of the brain was performed.

Based on the clinical history and the images, what is the most likely diagnosis?

a) Neurotoxoplasmosis


b) Primary CNS lymphoma


c) Progressive multifocal leukoencephalopathy


d) Neurocryptococcosis


Image analysis 

Image 1: Magnetic resonance of the brain, axial view, at the level of the frontal lobes, T1-weighted, before the intravenous contrast injection (A); and T1-weighted, after the intravenous contrast injection (B). (A): hypointense lesion in the right frontal area representing edema. (B): hypointense lesion in the right frontal area with ring enhancement (green line) and concentric target sign (yellow arrow), surrounded by hypointense area of perilesional edema (red line), besides hypointense lesions in the occipital area (small red circles).


Image 2: Magnetic resonance of the brain, at the level of the basal ganglia, T2-weighted (A) and FLAIR (B). Multiple lesions, mostly hyperintense, in the thalamus, basal ganglia and right frontal lobe areas (red lines). 


- Neurotoxoplasmosis is the most common cause of brain lesions in patients with HIV infection, representing the first suspicion in HIV+ patients with neurologic deficits;

- All HIV+ patients presenting compatible clinical signs and suggestive imaging of neurotoxoplasmosis should be empirically treated for this infeccion;

- Its lesions are located preferably in the basal ganglia, but it can affect any brain region;

- The concentric target sign is present in about 30% of the cases and is highly suggestive of neurotoxoplasmosis with high specificity but low sensibility.


- Ministério da Saúde, Secretaria de Vigilância em Saúde, Departamento de Vigilância, Prevenção e Controle das Infecções Sexualmente Transmissíveis, do HIV/Aids e das Hepatites Virais. Protocolo Clínico e Diretrizes Terapêuticas para Manejo da Infecção pelo HIV em Adultos. Brasília: Ministério da Saúde; 2018;

- Moreira R, Roberto Bollela V, de Carvalho Santana R, Fonseca França Ribeiro F. Infecções Oportunistas do Sistema Nervoso Central em HIV/AIDS na Emergência. Revista Qualidade HC - 2018 edition [Internet]. 2018 [cited 10 June 2019];. Available from:;

- Pereira-Chioccola V, Vidal J, Su C. Toxoplasma gondii infection and cerebral toxoplasmosis in HIV-infected patients. Future Microbiology. 2009;4(10):1363-1379;

- Guimarães Gonçalves F, Ramos Barra F, de Lima Matos V, Lemos Jovem C, Luís Faria do Amaral L, delCarpio-O'Donovan R. Sinais em neurorradiologia - parte 1. Radiologia Brasileira [Internet]. 2011 [cited 10 June 2019];44(2). Available from:;

- Bowen L, Smith B, Reich D, Quezado M, Nath A. HIV-associated opportunistic CNS infections: pathophysiology, diagnosis and treatment. Nature Reviews Neurology. 2016;12(11):662-674.


Aristeu Mascarenhas da Fonseca, 3rd year medical student at Universidade Federal de Minas Gerais (UFMG)

E-mail: aristeumascarenhas[at]


Helena Duani, professor of the Internal Medicine department at UFMG and infectious disease doctor at the Hospital das Clínicas of UFMG.

E-mail: hduani[at]

Carlos Magno, neuroradiologist at the Hospital das Clínicas of UFMG.

E-mail: carlosbresil[at] 


Lara Hemerly, Mirella Diniz, Raphael Dias, Gustavo Vargas, Felipe Lopes, Professor José Nelson Mendes Vieira; Professor Viviane Santuari Parisotto Marino.

Test question

(2014 Medical Residency Examination – Universidade Federal Fluminense)

Hypodense lesion with ring enhancement after the intravenous contrast injection is an nonspecific finding at the computed tomography that can correspond to many etiologic agents of inflammatory-infectious processes. In the immunocompromised patient, especially the HIV+, the most common etiologic agent in Brazil is:

a) Tuberculosis


b) Blastomycosis


c) Aspergillosis


d) Thrush


e) Toxoplasmosis



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