Recurrent Multi-territory Thromboembolism As the Initial Presentation of Pancreatic Adenocarcinoma and Suspected Nonbacterial Thrombotic Endocarditis

Nonbacterial thrombotic endocarditis (NBTE), also known as Marantic endocarditis, is an uncommon complication of malignancy that may cause systemic embolization. We report a 74-year-old woman who developed a right gastrocnemius deep vein thrombosis followed by recurrent right middle cerebral artery occlusions requiring two mechanical thrombectomies. Her subsequent course was complicated by further deep vein thrombosis, pulmonary embolism, and acute limb ischemia. Repeat echocardiography demonstrated mitral valve vegetations, initially raising concern for infective endocarditis. However, repeated blood cultures and cultures of retrieved thrombotic material were negative. Imaging revealed widespread metastatic disease, and biopsy of a left supraclavicular lymph node confirmed metastatic pancreatic adenocarcinoma. The combination of recurrent arterial and venous thrombosis, advanced malignancy, and negative microbiological investigations favored a clinical diagnosis of NBTE. This case illustrates how extensive thromboembolic disease may precede the diagnosis of pancreatic cancer and highlights the diagnostic challenge posed by valvular vegetations in this setting.