Clinical presentation and imaging characteristics of occult lung cancer associated ischemic stroke.

We investigated the clinical and imaging characteristics of initial and recurrent strokes in patients with occult lung cancer associated ischemic stroke (OLCA-stroke). A retrospective review of all ischemic stroke patients with occult lung cancer in the absence of conventional stroke etiologies between 2005 and 2013 was conducted. We compared the initial and recurrent lesion patterns on diffusion-weighted MRI in patients with OLCA-stroke, with respect to vascular territory involved, number and size of lesions, clinical presentation, cancer subtypes, recurrences and fatalities, and outcome of survivors. Thirteen patients with confirmed OLCA-stroke were identified. All had elevated D-dimer levels, six had central lung cancer and seven had peripheral lung cancer. Eight (62%) had adenocarcinoma, and nine (69%) had metastasis. Ten (77%) patients had multiple lesions in multiple vascular territories. Twelve (92%) patients suffered recurrent strokes. Multiple small and large disseminated lesions in multiple vascular territories were more frequent in recurrent strokes in comparison with initial strokes. The middle cerebral artery was most frequently involved in recurrent strokes, followed by the posterior circulation territory and anterior cerebral artery, which were of similar frequency as initial strokes. Overall, 58% of patients had their first recurrent stroke within the first month, and 69% had a poor outcome, especially for those with multiple recurrent strokes and metastases. Occult cancer should be considered in the setting of multiple and recurrent embolic strokes within the short term in the absence of conventional stroke etiologies. The severity of malignancy and cancer treatments and stroke influenced the recurrences and outcome.