Trousseau's syndrome caused by bladder cancer producing granulocyte colony-stimulating factor and parathyroid hormone-related protein: A case report.

The present study reports a rare case of bladder cancer that caused Trousseau's syndrome, a malignancy-associated hypercoagulative state leading to venous or arterial thrombosis. A 38-year-old Japanese female patient experienced a sudden onset of visual field defects and lower limb weakness. Cerebral magnetic resonance imaging revealed multi-regional hypointense areas compatible with acute cerebral infarction. Despite the repeated administration of anticoagulant treatment with heparin, the condition could not be adequately controlled and thromboembolic events occasionally recurred. Several tumor markers, including carbohydrate antigen 19-9, cancer antigen 125, carcinoembryonic antigen, cytokeratin 19 fragment and squamous cell carcinoma antigen levels, were elevated. Consequently, computed tomography scans were performed, which revealed a massive bladder tumor with multiple bone and lymph node metastases. The patient also exhibited other paraneoplastic disorders, including leukocytosis due to granulocyte colony-stimulating factor (G-CSF) production, and hypercalcemia due to parathyroid hormone-related protein (PTHrP) production. Transurethral resection of the bladder tumor was performed, and the tumor was pathologically confirmed as urothelial cell carcinoma. Immunohistochemical testing revealed positive staining for G-CSF and PTHrP. Despite undergoing gemcitabine/cisplatin-based systemic chemotherapy, the disease developed rapidly and the patient succumbed to the disease within 3 months of initial symptoms. The present case indicates that occult visceral malignancy should be considered in patients with unexplained thromboembolism.