A 16-year-old male immigrant from Southeast Asia was brought to the emergency department by EMS after witnessed having a seizure.
Click each image to the right to enlarge and view.
Image 1: CT without contrast
Image 2: T1 post-contrast
Image 3: T2 FLAIR
Image 4: Diffusion
Correct answer: D. CNS tuberculosis
Discussion: It is estimated that 5 percent to 10 percent of TB patients have some form of extrapulmonary disease; CNS involvement occurs in approximately 1 percent of all TB patients (1).
The most common clinical manifestation of CNS spread of disease is meningitis. Abscess formation and intracranial arteritis are not uncommon. Tuberculomas are a rare manifestation of CNS disease and predominantly occur in children (2). Extrapulmonary disease occurs via hematogenous spread from a primary lung infection. Tuberculomas may result when meningeal disease reaches the brain parenchyma via spread through small arterial penetrators or veins.
Imaging findings: CNS Tuberculomas are typically multiple ovoid or aggregated multilobulated lesions in distributed throughout the brain parenchyma. Unenhanced CT may show variable attenuation and calcified lesions. On MRI, lesions are typically T1 hypo- or iso-intense to brain parenchyma with extensive vasogenic edema. Lesions often demonstrate thick rim-enhancement with caseation or homogeneous nodular enhancement in smaller/non-caseating lesions. Centrally restricted diffusion is also a common finding. Over time, chronic/indolent disease may produce changes including calcified lesions, parenchymal atrophy, and areas of local ischemia/infarct.
- Cavernomas: Next most likely diagnosis; however this is unlikely in this case given extensive vasogenic edema.
- Neurosarcoidosis: Typical imaging appearance is leptomeningeal enhancement without calcification.
- Intraparenchymal meningioma: Meningiomas are dural based.
- Neurocystercercosis: Scattered small lesions in the parenchyma and at the gray-white junction; large aggregates are not typical. Calcification occurs in late-stage disease.
Note: This quiz is for entertainment purposes, and all answers are anonymous.