Retinal Vasculopathy With Cerebral Leukoencephalopathy Mimicking a Brain Tumor: A Case Report.

Retinal vasculopathy with cerebral leukodystrophy (RVCL) is an adult-onset, autosomal dominant disorder caused by heterozygous C-terminal frameshift mutations in TREX1, leading to mislocalization of its normally perinuclear exonuclease. Patients typically present with progressive visual impairment and neurological decline, while brain magnetic resonance imaging (MRI) commonly demonstrates punctate white matter lesions or tumor-like rim-enhancing masses. We report the case of a 53-year-old woman who initially presented with progressive headaches, followed by visual loss, cognitive impairment, and focal neurological deficits. Brain MRI revealed a left frontal white matter rim-enhancing lesion highly suggestive of a high-grade glioma. Histopathological evaluation demonstrated ischemic white matter injury, marked vascular hyalinization with fibrinoid necrosis, and prominent dystrophic calcifications. Ultrastructural analysis revealed multilaminated basement membranes and granular osmophilic deposits. Genetic testing, which had been performed previously, later demonstrated a pathogenic TREX1 mutation, establishing the diagnosis of RVCL. This case highlights the importance of considering RVCL in the differential diagnosis of tumor-like white matter lesions and underscores the clinical value of detailed histopathological and ultrastructural characterization, which is seldom available in reported cases.