Lithopedions, also known as stone babies, are a rare phenomenon which occurs most commonly when a fetus dies during an ectopic pregnancy.
The estimated incidence is at ~1.5 to 1.8% of abdominal ectopic pregnancies 4.
If the deceased 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. Lithopedions 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.
History and etymology
Derives from the Ancient Greek roots, litho (λίθο) = stone and paedion (παιδίον) = child.
Diagnosis is usually straightforward, but differential hypotheses might include:
- 1. Burger NZ, Hung YE, Kalof AN et-al. Lithopedion: laparoscopic diagnosis and removal. Fertil. Steril. 2007;87 (5): 1208-9. doi:10.1016/j.fertnstert.2006.11.065 - Pubmed citation
- 2. Sun G, Li M, Lu Y. Unrecognized lithopedion with 35 years' evolution diagnosed on computed tomographic scan. Fertil. Steril. 2010;94 (1): 341-2. doi:10.1016/j.fertnstert.2009.12.019 - Pubmed citation
- 3. Lachman N, Satyapal KS, Kalideen JM et-al. Lithopedion: a case report. Clin Anat. 2001;14 (1): 52-4. doi:10.1002/1098-2353(200101)14:1<52::AID-CA1009>3.0.CO;2-H - Pubmed citation
- 4. Santoro G, Laganà AS, Sturlese E, Giacobbe V, Retto A, Palmara V. Developmental and clinical overview of lithopaidion. (2014) Gynecologic and obstetric investigation. 78 (4): 213-23. doi:10.1159/000358828 - Pubmed