Infective Endocarditis With Origin in Orbital Vascular Malformation and Maxillary Sinusitis: A Case Report and Review of Four Patients in the Literature.

Infective endocarditis is a life-threatening disease and the early diagnosis is crucial for a better outcome. We report an old adult who developed infective endocarditis in association with new-onset maxillary sinusitis as well as proptosis, which was caused by an orbital mass lesion in the background of pre-existing orbital vascular malformation. A 74-year-old woman was found incidentally to have right orbital vascular (venous) malformation by head magnetic resonance imaging when she was hospitalized for left dorsal pontine infarction. No paranasal sinusitis was noted at that time. She was well until half a year later when she developed fatigue and appetite loss for two days. At the same time, she had proptosis on the right side but did not have a fever. Blood examinations showed leukocytosis and a marked increase of C-reactive protein to 22 mg/dL as well as a moderate increase of bilirubin and liver enzymes. Emergency computed tomography scans from the head to abdomen showed nothing to be noted except for maxillary sinusitis and a retrobulbar orbital mass on the right side, which was in the same location as pre-existing vascular malformation. She began to have empirical antibiotics suspected of infective endocarditis. Head magnetic resonance imaging showed ischemic lesions in the right parietal lobe. Transthoracic and transesophageal echocardiography showed mitral valve regurgitation but no apparent vegetation. was detected by blood culture and the antibiotics were switched to intravenous penicillin G for 32 days. She was discharged in healthy condition with no proptosis. The orbital vascular malformation might serve as a route for infective endocarditis with the infectious origin in maxillary sinusitis. Maxillary sinusitis would be a predisposing factor for the development of infective endocarditis, and proptosis caused by an infectious focus of abnormal vascular channels in the orbit would lead to the early diagnosis of infective endocarditis. The present patient is unique in showing infective endocarditis in association with orbital vascular malformation.