Nonbacterial endocarditis presenting as a right ventricular tumor in assumed Behçet’s disease

Excerpt

A 20-year-old man was admitted to hospital with a 2-month history of recurring fever attacks of up to 41 °C. Whereas physical examination have no hints of an inflammatory focus, laboratory investigations suggested a bacterial infection (leukocytosis up to 17.9 10³/µl, neutrophil granulocytes up to 86 %, C-reactive protein levels up to 14.6 mg/dl). Furthermore, laboratory analysis revealed microcytic hypochromic anemia (minimum hemoglobin 8.4 g/dl, mean corpuscular volume 58 fl), which was caused by a beta thalassemia minor. During the diagnostic work-up, computed tomography of the lung revealed pulmonary embolism. Transthoracic and transesophageal echocardiography showed a mass in the right ventricular cavity but no valvular vegetations. Repeated blood cultures remained negative. For further analysis of the right ventricular mass, cardiac magnetic resonance imaging (MRI) was performed. Cardiac MRI showed a mass of 1.8 × 1.7 × 1.4 cm in the right ventricular cavity adjacent to the papillary muscles (Fig. 1) with a slightly hyperintense signal compared with the myocardium in the cine steady-state free precession (Fig. 1 a, b) and T2-weighted turbo spin echo (Fig. 1 d) images and an isointense signal in the T1-weighted turbo spin echo (Fig. 1 c) images. First-pass perfusion imaging (Fig. 1 e, f) revealed a contrast enhancement of the mass. Whereas the images in the early phase after contrast injection revealed signal intensity comparable to that of the myocardium (Fig. 1 g), the images acquired 10 min after contrast injection (Fig. 1 h) revealed a focal late contrast enhancement within the mass. Although the Duke criteria for diagnosis of infectious endocarditis were not fulfilled, endocarditis was assumed in view of the MR features of the right ventricular mass and the patient’s history. Since antibiotic therapy with gentamicin, sultamicillin, and vancomycin showed no effect, surgical resection of the right ventricular mass was performed. Histopathological analysis of the resected mass showed a nonbacterial endocarditis parietalis (Fig. 2). After resection of the right ventricular mass, the fever attacks recurred, and, again, blood cultures showed no causative organism. Further antibiotic therapy with imipenem/cilastatin and erythromycin, as well as treatment with erythromycin, failed. Moreover, during the subsequent hospitalization, the patient developed a four-level deep vein thrombosis of the lower extremities as well as thromboses of the brachiocephalic veins. Failure of multiple antibiotic therapies, the fact that multiple blood cultures remained negative, the B symptoms, and the development of multiple vein thromboses led us to consider that the patient might suffer from an immune-mediated disease. Owing to the described clinical features and the origin of the patient, Behçet’s disease was supposed, although the criteria for diagnosis of Behçet’s disease of the international study group for Behçet’s disease were not fulfilled. Furthermore, genetic analysis showed mutations indicative of familial Mediterranean fever. Systemic corticoid therapy resulted initially in a rapid termination of the fever attacks. Because of the recurrence of the fever attacks under corticoid therapy, colchicine was administered additionally. This medication resulted in the termination of the fever attacks, declining inflammatory parameters, as well as in an improved general health condition. …