Atypical marantic endocarditis

Marantic endocarditis is a rare non-infectious endocarditis that mostly affects the aortic and mitral valves. It is often an autopsy finding that is most commonly seen in advanced malignancies thought to be due to a hypercoagulable state. When diagnosed antemortem, it typically presents with signs and symptoms of embolisation. We report a case of a 44-year-old Caucasian man with marantic endocarditis secondary to metastatic small cell lung cancer. Our patient presented with a short history of lower back pain with no signs/symptoms of embolisation, and a pansystolic murmur on initial physical examination. Serial blood cultures were negative and transthoracic echocardiography revealed vegetation on the posterior leaflet of the mitral valve. Further imaging in the form of MRI spine and CT thorax/abdomen/pelvis showed pulmonary lesions with liver and bony metastasis. Subsequent image-guided biopsy confirmed metastatic small cell lung cancer of T1N2M1c grade, which was treated with palliative chemotherapy and radiotherapy.