Childhood primary angiitis of the central nervous system with metachronous hemorrhagic infarcts: a postmortem study with clinicopathologic correlation.

This neuropathologic case study illustrates the discovery of metachronous hemorrhagic infarcts insinuating round mass-like lesions by magnetic resonance imaging in the setting of childhood primary angiitis of the central nervous system (cPACNS) raising diagnostic awareness of this unusual presentation in a clinical and neuroimaging context. The report underscores the importance of recurrent vasculitis-induced ischemic brain damage as a pathologic correlate of relapsing cPACNS and offers a critical reappraisal of common imitators as well as a clinicopathologic approach to differential diagnosis. Attention is drawn to the caveat that although magnetic resonance imaging findings at initial presentation may not be typical for stroke, they later exhibit attributes of cerebral infarction at both the subacute and chronic stages. A pattern of cPACNS characterized predominantly by multiple petechial-like cortical hemorrhages with pathologic features of hemorrhagic infarcts is recognized. The present study lends credence to the practice of a rigorous autopsy-based approach aimed at a better understanding of the anatomic pathology and biology of cPACNS and at facilitating prospective neuroimaging and biopsy-based surgical pathology correlations, ultimately enhancing diagnostic accuracy in clinical settings. Although PACNS is, by definition, a diagnosis of exclusion, it should be considered from the outset in the differential diagnosis of ischemic stroke or hemorrhagic stroke or of unusual and relapsing intra-axial mass-like CNS lesions in children, necessitating appropriate pathologic evaluation of brain biopsy specimens.