Endgames Spot Diagnosis

A boy with a sac-like protrusion at the occipital region

BMJ 2016; 353 doi: https://doi.org/10.1136/bmj.i2073 (Published 14 April 2016) Cite this as: BMJ 2016;353:i2073
  1. Yong-Hai Zhou, consultant paediatrician1,
  2. Ming-Hua Zheng, consultant hepatologist2
  1. 1Department of Paediatrics, Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, China
  2. 2Department of Hepatology, Liver Research Centre, First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, China
  1. Correspondence to: M-H Zheng zhengmh{at}wmu.edu.cn

A 1 year old boy presented to the neurosurgery clinic with a sac-like protrusion at the occipital region that had been present since birth. He was born at full term by caesarean section. He had no neurological symptoms and the swelling had not enlarged since birth. On examination, his head circumference was normal for age. The protrusion was 2.5×2.5 cm and his cry impulse was positive. A systemic examination found no associated anomalies. Magnetic resonance imaging of the head was performed (fig 1). What is the diagnosis?

Answer

The diagnosis is occipital encephalocele.

Discussion

The image shows a focal defect of the occipital bone, with herniation of a cerebrospinal fluid filled sac and brain tissue through the defect, indicating that the boy has an encephalocele (fig 2).

Figure2

Fig 2 Axial T2 weighted magnetic resonance image of the brain showing the occipital encephalocele (arrow)

Encephalocele is a rare congenital malformation in which the meninges and brain tissue herniate as the result of a skull defect. It is a type of neural tube defect and its incidence is thought to range from 1 in 10 000 to 5 in 10 000 live births,1-3 with about 75% being occipital.3 Cranium bifidum with encephalocele should be repaired surgically. The aim of surgical treatment is to cut off the sac and to reposition and protect the functional neural tissues. Prognosis depends on the anatomical site, the volume of neural contents, and coexisting malformations. One study found that patients with occipital encephalocele had a worse prognosis than those with other types of encephalocele.4 All pregnant women should be screened for using prenatal ultrasonography. Fetal magnetic resonance imaging, which can also diagnose this condition, is increasingly used in UK teaching hospitals. Moreover, consumption of folic acid before pregnancy and in the early stages of pregnancy could help to prevent such defects. Magnetic resonance imaging can confirm this disease after birth.

Footnotes

  • Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following interests: none.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

  • Patient consent obtained.

References

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