Objective: A pathologic human embryo 3 mm long affected by a “ventral prolaps” was present in a product of conception implanted within the Fallopain tube. The gestational age was 7 weeks. The malformation was characterized by a deep protrusion of the embryonal body (containing the medullary tube and the notochord adherent to the ceiling of the yolk sac) through the umbilical ring of the germ disc delineated by ectoderm covered mesenchymal streaks with primordia of the umbilical veins. Similar two affected embryos were depicted by Kollmann in his Handatlas in 1907, but were considered normal. Design: Case report. Setting: Institute for the Care of Mother and Child, Prague, Institute for Postgraduate Medical Education, Prague. Results: Impanted product of conception found within the Fallopian tube exhibitted a characteristic embryonic defect described as the „ventral prolaps”. Conclusion: Ventral prolaps of the embryo represents a characteristic embryonal malformation of unknown developmental significance.

        Key words: embryo, ventral prolaps, ectopic pregnancy