An acardiac twin with advanced brain development and a minor form of holoprosencephaly and intracerebral retina-like pigmented tissue: a case report and review of the literature.

ABSTRACT

The development of an acardiac twin in a monochorionic multiple pregnancy is a rare and severe complication of abnormal placental vascular anastomoses. These malformed fetuses present with a very bizarre morphology and a plethora of different malformations. However, all acardiac twins show either a complete absence or an anlage of the heart. Cerebral development is usually poor. We report, according to our review of the literature, for the first time, a very unusual case of acardius with features of acardius amorphus and acormus (fused head and malformed axial skeleton without macroscopically detectable internal organs) with lobar holoprosencephaly and intracerebral pigmented retina-like tissue.