Hydatid cyst of the interventricular septum causing obstruction of the right ventricular outflow tract: cross-sectional echocardiographic, angiographic and pathological findings

Cardioc echinococcal cysts rarely involve the interventricularseptum; when they do, they cause symptoms mainly related tothe compression of the atrio-ventricular conduction pathways.Mild obstruction of the right ventricular outflow tract hasalso been described in some cases. In the case reported here,an unusual, large hydatid cyst located in the interventricularseptum produced a marked, symptomatic obstruction of the rightventricular outflow tract (more than 100 mmHg gradient). Surgicalresection of the cyst was complicated by a ‘stone heart’syndrome, probably because of a severely affected right ventricle.Cross-sectional echocardiography gave the exact site and aetiologyof the mass. On the basis of these non-invasive findings, earlysurgery should be performed on asymptomatic patients to thereduce the risk of life-threatening evolutions.