Isolated pulmonary valve endocarditis with pulmonary annular abscess in a patient of Noonan syndrome.

Right-sided endocarditis is a rare entity, with various series reporting an incidence of 5%-10%. Pulmonary valve (PV) is not only the least commonly involved valve in infective endocarditis (IE), with an incidence of 1.5%-2%, but 'isolated' pulmonic valve endocarditis (PVE) without tricuspid valve involvement is even rarer with limited published data. We report a middle-aged man with Noonan syndrome and a dysplastic PV with severe pulmonary stenosis. He presented with a large isolated mobile PV vegetation with moderate pulmonary regurgitation (PR). Initially, he was managed conservatively, but due to persistent fever, pulmonary regurgitation and evidence of pulmonary annular abscess extending into the right ventricular outflow tract, he required surgical intervention. Considering the low incidence of isolated PVE, it poses a challenge for physicians in prompt diagnosis and timely management of the infection.