Spanish English Portuguese

Congenital Abnormalities

Interactive App

Anencephaly » Skull Q00.0


A congenital malformation characterized by the total or partial absence of the cranial vault, the covering skin, and the brain missing or reduced to small mass. Includes craniorachischisis. Incl. infants with iniencephaly and other neural tube defects as encephalocele or open spina bifida, when associated with anencephaly.
Excludes acephaly, that is, absence of head observed in amorphous acardiac twins.
The total ou partial absence of tha cranial vault, scalp and brain, does not permit the clinical distinction of ANENCEPHALY (Neural tube defect: ectodermal) from ACRANIA (Defect of notocorda: mesodermal).
ACRANIA is a primary or disruptive cranial defect with different degrees of involution of the encephalic mass due to aseptic necrosis because of the direct exposure to the amniotic fluid.
It may be called HOLOACRANIA or MEROACRANIA, if the cranial defect does involve or not the foramen magnum, respectively.
When the brain extrudes throughout the cranial defect it is named EXENCEPHALY, which is just a descriptive term.
When not associiated with anencephaly/ acrania, it excludes craniorachisquisis [Q00.1] and iniencephaly [Q00.2].
It should also exclude acephaly [Q89.8], i.e., absence of the head, found in amorphous twins, although ICD10 includes it together with anencephaly.
For hydranencephaly: See Directed Semiology: flashlight series.
Image 1
Photo 1-2.Holoacrania
3. Holoacrania
4. Holoacrania
Image 6
Photo 1.Holoacrania
Image 7
Photo 1. Meroacrania
2. Meroacrania
3. Meroacrania
4. Meroacrania
Image 12
Photo 1. Acrania and exencephaly
2. Acrania and exencephaly
Image 15
Photo. Acrania and exencephalia with the whole brain outside of the skull. What it is seen adherent to the skull is not placenta, but encephalum, neither umbilical cords, but probably amnion. The placenta was not near the skull.