Fetal diastematomyelia: MR imaging: A case report

In utero Diagnosis of Spinal Dermal Sinus

INTRODUCTION

Congenital dermal sinus (CDS) is an open neural tube defect (NTD) that occurs in 1 in 2,500 births a year and often goes undetected until patients present with complications like infection and neurological deficits. Early diagnosis and repair of CDS may prevent formation of these complications. In utero diagnosis of these lesions may improve long-term outcomes by enabling referral to specialty services and planned postnatal repair; however, only 2 such cases have been reported in the literature. We present a third case of in utero diagnosis of CDS with a description and discussion of findings from surgical exploration and pathology.

CASE PRESENTATION

Routine prenatal ultrasound scan detected a tethered cystic structure arising from the back of the fetus at 20 weeks of gestation. Dedicated fetal ultrasound confirmed the presence of a cystic lesion protruding through a lamina defect, while fetal magnetic resonance imaging showed an intact spinal cord and meninges, suggesting a diagnosis of CDS. Neurosurgery followed along closely and took the child for surgical exploration on day 2 of life. A fibrous stalk with an intradural component and associated cord tethering was excised. Histology showed fibrous tissue without an epithelial-lined lumen.

CONCLUSION

CDS is a form of NTD that occurs from nondisjunction of the cutaneous ectoderm and neuroectoderm during formation of the neural tube. Slight differences in how this error occurs can explain variations seen in this spectrum of disease, including CDS without an epithelial-lined lumen as seen in this case. Newborns with CDS can go undiagnosed for years and present with long-term complications. Fetal imaging can assist in early recognition and surgical excision of CDS in newborns.

MRI Characteristics of Split Cord Malformation

Split cord malformation (SCM), a subtype of spinal dysraphism, represents a rare entity of congenital malformation in the spine that occurs rarely in adults. SCM commonly presents with back pain. MRI is the gold standard for diagnosis. We report a case of a previously healthy 25-year-old woman who presented with lower back pain for a duration of 6 months. MRI confirmed a diagnosis of type I SCM. This case highlights the neuroimaging characteristics of SCM, although it might remain asymptomatic for many years. Surgical intervention might not be indicated in case of absent clinical complications.

MRI diagnosis of diastematomyelia in a 78-year-old woman: Case report and literature review

BACKGROUND

Diastematomyelia is a rare congenital malformation of the spinal cord, which belongs to the group of occult spinal dysraphisms. This disorder consists in the separation of the spinal cord into two parts in the sagittal plane (hemicords). Diastematomyelia may coexist with other spinal dysraphisms, such as myelomeningocele, meningocele, spinal lipoma, neuroenteric cysts or dermal sinuses and vertebral abnormalities, such as hemivertebrae, butterfly vertebrae or scoliosis.

CASE REPORT

We reported a case of a woman with a congenital defect of the spinal cord, in the form of diastematomyelia, which was diagnosed at the age of 78. The patient had been complaining of back pain for many years. The X-ray radiograms showed the fusion of vertebra L3-L4, defective fusion of posterior spinal bony elements L5-S1. Moreover, abnormal hair growth (hypertrichosis) in the lumbar region was found. The separation of the spinal cord was only diagnosed in MR imaging which was performed at the age of 78.

CONCLUSIONS

Diastematomyelia is mostly diagnosed in the prenatal period or in children; much less often in adults. This disorder has to be taken into account in differential diagnosis in patients with X-rays revealing defects of the spine in the form of hemivertebrae, butterfly vertebrae or the fusion of vertebrae, especially when there are additional skin lesions in the back area, at the level of the diagnosed osseous anomalies.