Streptococcus mutans pulmonary valve endocarditis complicated by septic pulmonary embolisms

2017-06-18 14:38:25

Category: Chest & Cardiac Imaging, Region: Thorax-Vessels, Plane: Axial

A 41 year old female with a history of cervical squamous cell carcinoma and pulmonic stenosis was admitted following a 2 week history of fever and shortness of breath. Family and social history were unremarkable. Examination revealed fever, tachypnea and a heart murmur. Initial laboratory workup revealed leukocytosis and acute kidney injury. She was started on intravenous fluids and started empirically on intravenous antibiotics. Overnight, the patient suddenly developed worsening tachypnea and hypoxia, without hemodynamic instability. Chest X ray imaging showed interstitial pulmonary edema (Figure 1). Modified Well’s score was concerning for high likelihood of pulmonary embolism. Computed tomographic pulmonary angiography revealed a large filling defect in the bifurcation of the main pulmonary artery consistent with a large pulmonary embolus without evidence of right heart strain (Figures 2 - 3), multiple peripheral pulmonary cavitating nodules in random distribution throughout the lung concerning for septic embolisms or metastatic disease and signs of pulmonary interstitial edema (Figures 4 - 5). Subsequent transthoracic echocardiogram showed no vegetations and Doppler imaging of deep pelvic and lower extremity veins was unrevealing. Troponin I and serum BNP where negative. The patient was started on an intravenous heparin drip, supplemental oxygen, continued on antibiotics and placed on diuretics. Blood cultures returned positive for Streptococcus mutans. The patient then evolved unfavorably with episodes of tachycardia, fever and tachypnea. Repeat CT imaging 10 days after initial scan showed interval increase in pulmonary nodules (Figure 6) and consolidations (Figure 7), concerning for an infectious etiology, and a new embolus in the right upper lobe pulmonary artery (Figure 8). Despite broadened antibiotic treatment according to culture susceptibilities the patient continued to evolve unfavorably, now with increasing leukocytosis and creatinine. She underwent subsequent pulmonary artery exploration and embolectomy. An organized pulmonary artery clot measuring 3.5 x 2.5 x 1.5 cm attached to the anterior wall of the pulmonary artery and a 5mm mass in the posterior pulmonary valve annulus representing a possible endocarditis focus where found. Both were excised and the pulmonary valve was reconstructed. Pathology report from the embolus revealed a clot with multiple microorganisms. The patient evolved favorably with resolution of the leukocytosis, tachycardia, tachypnea, acute kidney injury and fever. Subsequent blood and surgical specimen cultures where negative. The patient was discharged after on postoperative day 14 with a 6 week course of antibiotics.