Background and purpose: Cancer patients with cryptogenic stroke often have high plasma D-dimer levels and lesions in multiple vascular regions. Hence, if patients with cryptogenic stroke display such characteristics, occult cancer could be predicted. This study aimed to investigate the clinical characteristics of cryptogenic stroke as the first manifestation of occult cancer and to determine whether plasma D-dimer levels and lesions in multiple vascular regions can predict occult cancer in patients with cryptogenic stroke. Methods: Between January 2006 and October 2015, data on 1225 patients with acute ischaemic stroke were extracted from the stroke database of Osaka University Hospital. Among them, 184 patients were classified as having cryptogenic stroke, and 120 patients without a diagnosis of cancer at stroke onset were identified. Clinical variables were analyzed between cryptogenic stroke patients with and without occult cancer. Results: Among 120 cryptogenic stroke patients without a diagnosis of cancer, 12 patients had occult cancer. The body mass index, hemoglobin levels and albumin levels were lower
plasma D-dimer and high-sensitivity C-reactive protein levels were higher
and lesions in multiple vascular regions were more common in patients with than in those without occult cancer. Multiple logistic regression analysis revealed that plasma D-dimer levels (odds ratio, 3.48
95% confidence interval, 1.68–8.33
P = 0.002) and lesions in multiple vascular regions (odds ratio, 7.40
95% confidence interval, 1.70–39.45
P = 0.01) independently predicted occult cancer. Conclusions: High plasma D-dimer levels and lesions in multiple vascular regions can be used to predict occult cancer in patients with cryptogenic stroke.