PMC7201472_01
(a) Left to right: computed tomography (CT), fluid-attenuated inversion recovery (FLAIR), T1 post-contrast, and susceptibility-weighted imaging (SWI) 13 days after admission showed minimal findings on CT, but FLAIR hyperintensities and petechial hemorrhages on T1 and SWI images (arrows). These had progressed compared to initial imaging (not shown). (b) Left to right: Carotid and cerebral angiography showing irregular corrugated and beaded appearance of the cervical carotid arteries and subtle intracranial vessel narrowing (arrows), and two new foci of restricted diffusivity on diffusion weighted imaging (DWI) in the bilateral centrum semiovale consistent with interval infarcts (arrows). Note: there was another infarct in the left centrum semiovale on an adjacent slice not shown above.
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MRI of the brain was repeated 13 days after the initial scan (Figure 1(a)), showing two new foci of restricted diffusivity in the left centrum semiovale consistent with interval infarcts. Cerebral angiography showed irregular corrugated and beaded appearance of the cervical carotid arteries, thought to be consistent with chronic fibromuscular dysplasia (Figure 1(b)).
(a) Left to right: Repeat CT, FLAIR, T1post, and SWI showing marked interval progression of hemorrhages on CT and SWI with surrounding edema on FLAIR and subtle foci of enhancement on T1 post-contrast images (arrows). The vasogenic edema and moderate-sized right temporoparietal hemorrhage caused cerebral edema and midline shift, and there were multiple additional petechial hemorrhages. There was also new sulcal FLAIR signal with subtle enhancement consistent with blood-brain barrier breakdown. (b) Left to right: Repeat catheter angiography showed a new right cervical internal carotid artery dissection on carotid angiography (arrow), progression of luminal irregularities in the distal the middle cerebral artery and the anterior cerebral artery branches (arrows), and new areas of cytotoxic edema/infarction on DWI (arrows).
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High-resolution vessel wall MRI did not show arterial wall enhancement to suggest vasculitis. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scan of the brain (Figure 2) and computed tomography (CT) of the chest, abdomen, and pelvis were unrevealing.
(a) FDG-PET scan of the brain demonstrated mildly diminished FDG uptake in the left more than right bilateral temporal, frontal, and parietal lobes as well as the in the posterior cingulate, precuneus and the primary visual and visual association cortices. The most prominent metabolic reduction was in the left frontal association cortex. There were no focal areas of hypermetabolism in the mesial temporal lobes or elsewhere. This diffuse pattern of mild metabolic changes was not specific for any inflammatory disease or other process, and most suggestive of a global encephalopathy with asymmetry due to more pronounced deficits in the left hemisphere. (b) PET scan of the body was notable for bilateral pleural effusions as well as pericardial effusion and scattered nonspecific ill-defined hypermetabolic pulmonary nodules with differential including infectious/inflammatory process or pulmonary lymphoma with max SUV (standard uptake value) of 6.8.
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Repeat catheter angiography showed a new right cervical internal carotid artery dissection in the distal extracranial portion as well as progression of luminal irregularities indicative of progressive vasculopathy (Figure 3(b)).
(a) Hematoxylin-and-eosin of the brain biopsy showed small cortical vessels pathologically distended with neoplastic lymphocytes (200X). (b) These cells were positive by immunohistochemistry for CD20, a B-cell marker (200X).
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These cells were pleomorphic, hyperchromatic, and displayed prominent nucleoli and occasional mitoses (Figure 4(a)). Immunohistochemistry revealed these malignant cells to be diffusely positive for CD20, a B-cell marker (Figure 4(b)).