Occipital encephalocele in a fetus at 34 postmenstrual weeks Occipital encephalocele in a fetus at 34 postmenstrual weeks. This patient presented for her first US exam at this gestational age. Microcephaly was also diagnosed (the biparietal diameter [BPD] and the head circumference were consistent with 26 postmenstrual weeks). (A) Frontal–2 section showing the longitudinal sulcus and apparently normal brain tissue. (B) Median section depicting the large bony defect in the occipital region marked by two black arrowheads. Brain tissue seems to protrude, pulling with it the posterior horn and the choroid plexus. (C), (D) Different sections of the encephalocele itself. (E), (F) Coronal sections by definition, showing the longitudinal sulcus and the dilated occipital horns and within it the choroid plexus. (G) A picture of the neonatal head showing the large occipital encephalocele. Clinical course: The neonate was found to have a chromosome 13q deletion and was admitted and discharged several times but reached the age of 1½ years. Another anomaly included absence of the thumbs. Cranioplasty was performed, which was complicated by wound infection and worsening hydrocephaly. A drain was placed; however, the infant was admitted several times to the hospital because of cerebrospinal fluid leak from the incision site. The infant had severe mental retardation and seizure disorder. The computed tomography (CT) studies showed that the encephalocele included the cerebellar hemispheres and a portion of the posterior horns (as diagnosed by the US pictures), in addition, partial agenesis of the corpus callosum with the splenium virtually absent was seen. Source: ANOMALIES OF DORSAL INDUCTION, Ultrasonography of the Prenatal Brain, 3e Citation: Timor-Tritsch IE, Monteagudo A, Pilu G, Malinger G. Ultrasonography of the Prenatal Brain, 3e; 2017 Available at: https://obgyn.mhmedical.com/DownloadImage.aspx?image=/data/books/2015/timor3_ach5_f023.png&sec=149926917&BookID=2015&ChapterSecID=149926810&imagename= Accessed: September 22, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved