Multifocal embolic stroke in metastatic colon cancer

Introduction: Cancer-associated stroke is an important clinical entity that develops as a result of malignancy-related hypercoagulability and is seen particularly in advanced-stage adenocarcinomas. Trousseau syndrome is a form of malignancy-associated embolic events. An acute ischemic lesion pattern involving multiple vascular territories simultaneously is an important radiological clue to cancer-associated embolic stroke. This report presents a multifocal embolic stroke pattern in a patient with metastatic colon adenocarcinoma.Case: A 66-year-old man had been followed for colon adenocarcinoma diagnosed in 2023 and had a colostomy. He was receiving FOLFIRI + bevacizumab for metastatic disease (right upper lobe of the lung, abdominopelvic region, and bilateral hilar involvement). He presented with loss of consciousness. He was lethargic, disoriented, and uncooperative, with rightward conjugate gaze deviation, dysarthria, and mild motor loss in both upper extremities. The NIHSS score was 7. Diffusion MRI showed multiple infarcts in the bilateral frontal, frontoparietal, and occipital cortical areas, as well as in the pons, cerebellum, and vermis, with corresponding hypointensities on ADC images. The simultaneous involvement of the bilateral anterior and posterior circulations by the lesions suggested a multifocal embolic process. Brain CT angiography showed no significant stenosis or occlusion. The ECG showed sinus rhythm, and echocardiography showed an EF of 60% and a left atrial diameter of 3.6 cm; no definite cardiac source of embolism could be demonstrated. TEE could not be performed because of clinical deterioration. The D-dimer level in the acute phase was 2.41. There was no evidence of thrombocytopenia, microangiopathic hemolysis, or infection. After therapeutic-dose enoxaparin, the D-dimer level fell to 0.56 on day 10 (Figure 1).Discussion/Conclusion: In the presence of active metastatic adenocarcinoma, acute ischemic lesions involving different vascular systems simultaneously should be evaluated for malignancy-associated hypercoagulability. In this patient, the absence of large vessel disease, the failure to demonstrate a cardiac embolic source, and the absence of findings of infection or a microangiopathic process, together with the multifocal embolic MRI pattern, pointed toward Trousseau syndrome. Although the lack of TEE does not definitively exclude nonbacterial thrombotic endocarditis, the clinical picture is consistent with malignancy-associated thromboembolism. In patients with metastatic colon adenocarcinoma, an acute ischemic lesion pattern in multiple territories should be evaluated for malignancy-associated hypercoagulability, beyond the classical stroke mechanisms. Diffusion MRI findings and the change in D-dimer level may provide an early diagnostic clue in cancer-associated embolic strokes.Keywords: