Acardius acephalus fetus--report of distinctive anatomical anomalies with regards to pathophysiology of TRAP sequence.

Acardiac fetuses are consequences of twin reversed arterial perfusion (TRAP). Here the authors present a case of 40-year-old gravida IX who gave birth to a healthy, 2,900 g female child by a cesarean section. Additionally amorphic 1,020 g maldeveloped fetus was removed. There was a diamnion monochorionic type of twin placenta with incorrect single umbilical arteries (SUA) both in umbilical cord of healthy fetus and in atrophic second umbilical cord. A malformed fetus developed a rather well formed lower leg with four digital foot and oval shape amorphous body mass with omphalocele and eventration of the intestines. X-ray picture showed well visible metatarsal and femur bone and anatomically undefined bones cluster in the central part. A cavity of fetal body contained intestines--the only one well-formed organ, nests of heterotopic pilosebaceous residues, remnants of adrenal glands, well-formed ganglia, and nests of neural tissue covered by neuroepithelium.