When strokes reveal a hidden malignancy: An atypical case of metastatic colorectal cancer with extensive thromboembolism

Cancer-associated thromboembolism and Trousseau's syndrome, which are paraneoplastic hypercoagulable states, are significant yet frequently underrecognized causes of cryptogenic stroke. We report a 71-year-old male who presented with recurrent embolic strokes and systemic thrombosis, later diagnosed with metastatic colorectal adenocarcinoma. Despite extensive investigations, no initial cancer-related symptoms were noted, and the diagnosis was made retrospectively after supraclavicular lymph node biopsy. The patient exhibited multi-territory infarcts, deep vein thrombosis, and renal and splenic infarcts, highlighting the aggressive thrombotic potential of malignancy-associated stroke. This case highlights the importance of early consideration of occult malignancy in cryptogenic embolic events, supporting comprehensive oncologic evaluation for unexplained hypercoagulable states.