Foetal acalvaria: a case report

D.M Casather,D.M.D.D Chandrasiri,S.M Fahim,W Abeykoon

doi:10.4038/sljm.v25i1.16

Abstract

Foetal acalvaria is an extremely rare congenital abnormality characterized by the complete or partial absence of skull bones with complete but abnormal development of the brain. A 27 year old multiparous woman was found to have an anencephalic foetus at 12 weeks of gestation. Foetal ultrasound scan at 36 weeks revealed a well formed brain without a cranium. The baby was delivered by cesarean section. The brain was displaced posteriorly due to the absence of supporting skull bones and was covered by a thick membrane. The neonate expired few hours after delivery. Identification of acalvaria antenatally allows the clinician to plan an appropriate timely management.

Highlights

Acalvaria is an extremely rare congenital malformation characterized by an absence of calvarial bones, dura mater and associated scalp muscles in the presence of basal skull bones, facial bones and complete but abnormally developed cranial contents covered by a scalp (1)
There is no identified cause for foetal acalvaria(3). It is a form of a congenital malformation that occurs as a result of faulty migration of the membranous neurocranium with normal placement of the embryonic ectoderm
This results in the formation of cranial contents in the absence of membranous bones but with an intact layer of skin over brain parenchyma (4)

Summary

Introduction

Acalvaria is an extremely rare congenital malformation characterized by an absence of calvarial bones, dura mater and associated scalp muscles in the presence of basal skull bones, facial bones and complete but abnormally developed cranial contents covered by a scalp (1). Acalvaria is usually a fatal anomaly and with only few survivors with this condition, treatment is limited. Patient was given routine antenatal care and at 36 weeks she had her normal obstetric examination and underwent foetal ultrasonography for further evaluation of the foetus. The brain showed normal vascular pattern with the circle of Willis on Doppler scan.

Results

Conclusion