Lithopaedion
Presentation
Incidentally-discovered calcified pelvic mass during workup for low back pain.
Patient Data
Extra-uterine calcified fetal skeleton on MPCR (multi-planar curved reformat) images.
Case Discussion
The patient recalled abnormal obstetric history 30 years ago. Otherwise, there was no relevant clinical or lab abnormality.
A lithopaedion (litho = stone; paedion = child), or stone baby, is a rare phenomenon which occurs most commonly when a fetus dies during an ectopic pregnancy. If the dead fetus is too large to be re-absorbed by the mother’s body it becomes a foreign body to the mother’s immune system. To protect itself from possible infection, the mother’s body will encase the fetus in a calciferous substance. The fetus is gradually mummified becoming a stone baby. Lithopaedions may occur from 14 weeks’ gestation to full term. It is not unusual for a stone baby to remain undiagnosed for decades and found incidentally when taking plain films for various reasons (like this case).
Credit: Dr Ahmed Haroun.