This is a routine ultrasound scan performed at 20 weeks of gestation for a 27-year-old woman G2P1. The right ventricle appears normal as does the ductal arch:

The left ventricle is filled by an echogenic mass that does not appear to deform it, but simply occupy the cavity:

The following abnormalities were detected in the heart:

• A dense left ventricle with almost no flow.
• A ventricular septal defect
• A small caliber aorta

An antenatal diagnosis of rhabdomyoma of the heart was made. The parents opted for termination of pregnancy. Histology of the fetal heart reveled a distended left ventricle, filled with clotted blood. There was no evidence of neoplasia. A rim of calcification was seen just deep to the endocardial lining of the left ventricle. The other chambers of the heart were normal. A diagnosis of idiopathic dystrophic ventricular calcification was made.