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Abstract
Objective: To identify the clinical and radiologic features that should raise suspicion for the pseudotumoral presentation of cerebral amyloid angiopathy–related inflammation (CAA-I).
Methods: We retrospectively reviewed the characteristics of 5 newly diagnosed and 23 previously reported patients in whom the CAA-I imaging findings were initially interpreted as CNS neoplasms.
Results: Most cases (85%) occurred in patients >60 years old. The clinical characteristics at presentation included subacute cognitive decline (50%), confusion (32%), focal deficits (32%), seizures (25%), and headaches (21%). Brain MRI demonstrated infiltrative white matter lesions that exhibited a loco-regional mass effect without parenchymal enhancement (93%). In general, these findings were interpreted as low-grade glioma or lymphoma. Eighteen patients (64%) underwent a biopsy, which was nondiagnostic in 4 patients (14%), and 6 patients (21%) underwent a surgical resection. The primary reason for the misinterpretation of the imaging findings was the absence of T2*-weighted gradient recalled echo (T2*-GRE) sequences on initial imaging (89%). When subsequently performed (39%), the T2*-GRE sequences demonstrated multiple characteristic cortical and subcortical microhemorrhages in all cases. Perfusion MRI and magnetic resonance spectroscopy (MRS), which were performed on a subset of patients, indicated markedly reduced relative cerebral blood flow and a normal metabolic ratio.
Conclusion: The identification of one or several nonenhancing space-occupying lesions, especially in elderly patients presenting with cognitive impairment, should raise suspicion for the pseudotumoral presentation of CAA-I and lead to T2*-GRE sequences. Perfusion MRI and MRS appear to be useful techniques for the differential diagnosis of this entity.
GLOSSARY
- Aβ=
- β-amyloid;
- CAA=
- cerebral amyloid angiopathy;
- CAA-I=
- CAA-related inflammation;
- DWI=
- diffusion-weighted imaging;
- FLAIR=
- fluid-attenuated inversion recovery;
- 1H-MRS=
- proton magnetic resonance spectroscopy;
- MRA=
- magnetic resonance angiography;
- MTT=
- mean transit time;
- rCBF=
- relative cerebral blood flow;
- rCBV=
- relative cerebral blood volume;
- SWI=
- susceptibility-weighted imaging;
- T2*-GRE=
- T2*-weighted gradient-recalled echo
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Supplemental data at Neurology.org
- Received April 10, 2015.
- Accepted in final form November 9, 2015.
- © 2016 American Academy of Neurology
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