Lithopedion

LITTLE'S DISEASE, see Infantile paralyses. LITHOPAEDION (from the Greek lithos—stone and paidion—child), a stony fetus. A fetus that dies and remains in the mother's body for a prolonged period may undergo various changes: in the early stages of development (up to the 3rd month), the fetus may be resorbed without a trace; later, when the skeleton has already formed, such resorption becomes impossible, and either suppuration, maceration, and skeletonization of the fetus occur, or its encapsulation and drying (mummification) followed by the deposition of lime salts—petrification, incorrectly called ossification by some, since no true bone tissue formation takes place. Such calcified fetuses bear the general name of lithopedion. Usually, calcification of the fetus occurs as a result of extrauterine pregnancy, but isolated cases of lithopedion formation in the uterine cavity have also been described. Kuchenmeister proposed distinguishing the following 3 types of fossilized fetuses. 1) Only the fetal membranes undergo calcification; the pseudo-fetus itself either mummifies or macerates; this type is called lithokeliphos (Greek keliphos—eggshell). 2) The amniotic fluid is resorbed, and the fetus fuses entirely or partially with the membranes; calcification begins at the membrane and gradually involves the adjacent parts of the fetus; this type, designated as lithokeliphopedion, is the most frequent. 3) Lithopaedion in the proper sense of the word, when the fetus is calcified devoid of membranes, as occurs in secondary abdominal pregnancy. Kuchenmeister's classification is generally accepted, but authors often still designate all types of fetal petrification by the general term lithopedion. Topically, lithopedions may be located in the same place as the embryos (see the diagram on page 241, vol. III). The duration of the lithopedion's stay in the mother's body ranges from 5 to 57 years (Kuchenmeister's case). Upon microscopic examination, the structure of most organs (liver, kidneys, lungs, skin, mucous membranes, etc.) is quite discernible; the brain and blood turn into a structureless, cholesterol-rich mass. The cross-striation of muscles is preserved especially well. It can be considered proven that lime salts are deposited in the lithopedion from the maternal blood, and not from the caseous vernix, as previous researchers assumed. The presence of a lithopedion in the mother's body is often not accompanied by any special symptoms: cases are known where women, having a lithopedion corresponding to a full-term fetus in the abdominal cavity, successfully underwent pregnancy and normal childbirth. In rare cases, the development of connective tissue adhesions around the lithopedion can lead to phenomena of intestinal obstruction.

M. Alekseev