Intravascular lymphoma (IVL) is a rare malignancy characterized by intraluminal proliferation of neoplastic lymphocytes within small and medium-sized vessels. In the rare cases of IVL spread to the CNS, the neurological manifestations are varied and often devastating. While most IVL cases are of B-cell lineage, intravascular T-cell lymphoma is exceedingly rare and aggressive. Diagnosis is challenging due to its nonspecific clinical and radiographic features and the need for invasive techniques to diagnose with certainty such as brain biopsy. 

Disseminated intravascular T-cell lymphoma can closely mimic CNS vasculitis and cause strokes. Diagnosis requires integration of multiple diagnostics when tissue biopsy is unavailable. Early endocrine abnormalities, such as central diabetes insipidus, may precede even the discovery of the cancer itself.  This case also underscores the importance of shared decision-making and aligning management with patient preferences in advanced neuro-oncologic disease. 

Disclosure: Dr. Lei has nothing to disclose. Dr. Al-Salaimeh has nothing to disclose.