Pathologic correlation of sonographic echogenic foci in the fetal heart

The goal of the current paper is to present, on the basis of six investigat ed fetal hearts, the pathological substrate of prenatally, sonographically diagnosed echogenic intramyocardial foci. The right ventricle, left ventric le, interventricular septum and papillary muscles of both ventricles of six hearts of the fetuses of highrisk pregnant women showing sonographically d iagnosed intramyocardial echogenic foci were investigated. At termination o f pregnancy all the women were between the 20th and the 24th week of gestat ion. Of the six cases, four were induced abortions and two were spontaneous abortions. For the control group we investigated the hearts of two fetuses without heart defects at the 22nd and 23rd week of gestation which had pro ven extracardial anomalies and a normal karyotype. Both cases were induced abortions which prenatally showed no echogenic cardiac foci. In all eight c ases a prenatal karyotyping was performed. In the six cases with echogenic foci the location and number of the foci were determined both prenatally an d by means of histologic sections; the size of the foci was measured as wel l. Histological staining was with routine haematoxylin-eosin; Masson-Goldne r was used for connective tissue; Kossa for calcification; and Berlin blue for haemosiderin. Histologically, in all six cases, intramyocardial calcifi cations surrounded by fibrotic tissue were in: papillary muscle of the left ventricle in six cases; papillary muscle of the right ventricle in one cas e; and the subendocardial myocardium of the right ventricle in one case. Fo ur cases had one, one case had two and one case had three calcified foci. T hree cases had cardiac and two cases had extracardiac anomalies. Four cases had chromosome anomalies: two were trisomy 21, one trisomy 13 and one trip loidy. The remaining two cases had a normal karyotype. No case showed patho logical changes of the chordae tendinae, myocardial cell necrosis or inflam mation. There were no patho-morphological differences between the intramyoc ardial calcifications of the papillary muscles in cases with chromosome ano malies and with normal karyotype. As the patho-morphological correlate of t he sonographically diagnosed echogenic foci, histological investigation on all six fetal hearts showed coarse intramyocardial calcifications surrounde d by myocardial fibrosis. Conventional histological methods gave no indicat ion of the cause of the intramyocardial calcifications. Copyright (C) 2000 John Wiley & Sons, Ltd.