A case of tricuspid valve non-bacterial thrombotic endocarditis presenting as pulmonary embolism in a patient with antiphospholipid antibody syndrome.

A 47-year-old woman with a medical history of Raynaud's phenomenon presented with fever, cough and shortness of breath. She was found to have left lower lobe consolidation and pleural effusion and was treated as a case of pneumonia. During the hospital course, her respiratory status worsened, and she was intubated on the third hospital day. To investigate the high A-a gradient, a Computerized Tomographic Pulmonary Embolism (CTPE) study was done which identified a large left lower pulmonary artery embolism. She was also found to have a new murmur, and an echocardiogram demonstrated a large lesion on tricuspid valve. However, multiple sets of her blood cultures came back consistently negative. Alternative diagnoses for culture-negative endocarditis were considered, and a full set of rheumatological workup was done. Laboratory tests were suggestive of antiphospholipid syndrome, hence the diagnosis of tricuspid valve Libman-Sacks endocarditis was made.