[Leiomyomas in pregnancy: ultrasonographic mimicry]

Leiomyoma is the most common tumor viewed by echosonography of the uterus. This report presents pregnancy with calcified leiomyoma of the uterus which simulated the head of the fetus, what was verified by echosonography. Woman, nullipara, 41 years old, in week 21 of pregnancy, was referred for echosonographic evaluation. Biochemical screening for Down syndrome, performed in week 17 of pregnancy, was positive. Fetal karyotype, obtained by amniocentesis, was normal (46 XX). In the case presented herein, diameter of leiomyoma was 48 mm, being equal to the diameter of the fetal head in 21st week of pregnancy. Due to calcifications on the surface of leiomyoma which were viewed on echosonography in the form of hyperechogenic border, this tumor looked like a head of the fetus. This echosonographic finding of two fetal heads in a single pregnancy was remarkable even for a gynecologist experienced in echosonographic examination.