FULL TEXT
Website developed by Bilal Mirza
CASE REPORT
APSP J Case Rep 2011; Vol. 2 (1)
OPEN ACCESS
Isolated Terminal Myelocystocele: A Rare
Spinal Dysraphism
Bilal Mirza,* Nasir Mahmood, Lubna Ijaz,
Tariq Khawaja, Imran Aslam, Afzal Sheikh
Department of Pediatric Surgery, The Children's
Hospital and the Institute of Child Health Lahore, Pakistan
*Corresponding Author's E-mail address:
blmirza@yahoo.com
APSP J Case Rep 2011; 2:
3
Competing Interest: None
Declared
ABSTRACT
Terminal myelocystocele is a rare spinal
dysraphism that present as lumbosacral mass. Magnetic resonance imaging (MRI) is
the modality of choice for preoperative diagnosis. A 2.5 months old female baby
presented with lumbosacral skin covered mass. There were no associated
neurological deficits. MRI of the lesion suggested two cysts, one of which was
continuous with the central canal of the spinal cord. At operation
terminal myelocystocele was found with tethering of the spinal cord. Untethering
of the spinal cord and repair of the myelocystocele performed with uneventful
recovery.
KEY WORDS Terminal
myelocystocele, Spinal dysraphism, Myelomeningocele
HOW TO
CITE
Mirza B, Mahmood N, Ijaz L, Khawaja T, Aslam I,
Sheikh A. Isolated terminal myelocystocele: a rare spinal dysraphism. APSP
J Case Rep 2011;2:3.
INTRODUCTION
Terminal
myelocystocele (TMC) is a rare spinal cord anomaly comprising 4-8% of all cases
of spinal dysraphism. Many a time it is associated with other congenital
anomalies such as anorectal malformations, abdominal wall defects, spinal
anomalies, urogenital anomalies etc. A number of these patients also have
associated neurological deficit; however few case reports described no
neurological deficits even after surgical repair. Isolated terminal
myelocystocele is rarely associated with neurological deficits [1,2]. This
report describes a rare type of spinal dysraphism.
CASE
REPORT
A 2.5-month-old female baby presented with a large lumbosacral
skin covered swelling which was present since birth. The patient was a product
of consanguineous marriage and born through vaginal delivery. The swelling
gradually increased in size. No abnormality was reported in relation to the
urination and defecation. Head circumference was 38cm and the neurological
examination was essentially normal.
The swelling was smooth, cystic,
fluctuant and transluminent, present over lumbosacral region measuring 8X6
cm2 in size with obliteration of natal cleft (Fig. 1).
Ultrasound showed a large cystic swelling with a defect in the spine through
which meninges were protruding. An MRI depicted a double compartment cystic
swelling. The inner cyst was a continuation of the spinal cord central canal
that too was dilated (hydromyelia). The cyst was seen protruding from a defect
in the posterior osseous elements of the lower lumbar and sacral vertebrae. The
spinal cord was tethered and low lying (Fig. 2,3).
The patient was
operated electively. A vertical incision was made in the midline and about 250ml
cerebrospinal fluid (CSF) drained. On further exploration of the external cyst,
another small cyst was found close to the spine.This cyst was also opened and
found to be in continuation with the central canal. The spinal cord ended
slightly cephalad with a fibrous band tethering the cord to the dorsal and
cephalic aspects of the inner cyst (Fig. 4). The operative diagnosis was
terminal myelocystocele. The untethering of the spinal cord was done after which
the water-tight repair of the defect performed. The postoperative recovery was
uneventful. The patient is on follow up and doing well.
DISCUSSION
Neural tube defects (NTD) are perhaps the most frequently
occurring congenital anomalies. The incidence is 1:1000 births, but variable
throughout the world. They usually occur during 3rd - 4th
gestational weeks. Embryologically, a failure of or defective neural tube
formation results in NTD. They may occur focally or at multiple points
[3].
Spina bifida is a term used to describe the NTD occurring in the
spine. It is classified as occulta and cystica/aperta. Spina bifida occulta is a
skin covered defect of the vertebral arches without neuronal involvement. Very
often found in the lumbo-sacral region and accounts for 10% of otherwise normal
individuals. The associated neurological dysfunction is absent or negligible. It
can be identified as a tuft of hair, a hemangioma, a sinus etc. at lower back.
Spina bifida cystic/aperta is a severe form of NTD and characterized by a defect
of vertebral arches through which meninges and the neuronal tissue protrudes
into a sac. They often associated with neurological deficits.
Meningomyelocele is usually associated with Arnold-chiari malformations and
hydrocephalus in more than 90% of cases [3]. Myelomeningocele is the frequently
occurring spina bifida whereas terminal myelocystocele accounts for 4-8% of all
cases of spinal dysraphism. Antenatal detection of the myelocystocele remained
challenging as to its differential diagnosis [3-6].
MRI, both fetal and
after birth, is an important diagnostic tool for the index condition. It can
delineate a cystic mass with septation in a coronal view. In sagittal view it
can show the continuation between central canal of the spinal cord and the inner
cyst. The communication of the outer cyst with subarachnoid space can also be
visualized. The other spinal and cord anomalies like tethered cord,
diastematomyelia, Arnold-chiari malformations, syringocele etc. can also be
detected with this tool. Antenatal ultrasonography in expert hands can delineate
spinal dysraphism but it is very difficult to diagnose myelocystocele with
accuracy even if performed after birth [4-6].
Myelocystocele have been
reported in cervical, thoracic and lumbosacral regions. Cervical myelocystocele
is infrequently associated with neurological deficit whereas terminal
myelocystocele is considered to have more neurological problems [6]. Our case
was an isolated myelocystocele with no neurological problem.
To
summarize, myelocystocele is a rare spinal dysraphism and rarer still is an
isolated terminal myelocystocele with very negligible neurological deficit. MRI
can diagnose the condition in-utero as well as postnatally. Excellent outcome
can be achieved by an early repair of the
defect.
REFERENCES
1. Kumar R, Chandra A. Terminal myelocystocele. Indian J
Pediatr 2002;69:1083-6.
2. McLone DG, Naidich TP. Terminal
myelocystocele. Neurosurg 1985;16:36-43.
3. Smith JL. Management of
neural tube defects, hydrocephalus, refractory epilepsy, and central nervous
system infections. In: Grosfeld JL O’Neill JA Jr, Coran AG, Fonkalsrud EW,
Caldamone AA. editors. Pediatric surgery. 6th ed. Chicago: Mosby
Elsevier, Year Book; 2006. p. 1987-96.
4. Yu JA, Sohaey R, Kennedy AM,
Selden NR. Terminal myelocystocele and sacrococcygeal teratoma: A comparison of
fetal ultrasound presentation and perinatal risk. Am J Neuroradiol
2007;28:1058:60.
5. Rossi A, Cama A, Piatelli G, Ravegnani M, Biancheri
R, Tortori-Donati P. Spinal dysraphism: MR imaging rationale. J Neuroradiol
2004;31:3-24.
6. Ochiai H, Kawano H, Miyaoka R, Nagano R, Kohno K,
Nishiguchi T, et al. Cervical (Non-terminal) myelocystocele associated with
rapidly progressive hydrocephalus and Chiari type II malformation. Neurol Med
Chir 2010;50:174-7.
IMAGES