|Year : 2020 | Volume
| Issue : 3 | Page : 286-289
Giant terminal myelocystocele: A case report
Gaurav Varshney, Deepak K Gupta
Department of Neurosurgery, All India Institute of Medical Sciences (AIIMS), New Delhi, India
|Date of Submission||25-Nov-2019|
|Date of Decision||29-Jan-2020|
|Date of Acceptance||27-May-2020|
|Date of Web Publication||06-Nov-2020|
Dr. Deepak K Gupta
Room No. 714, C.N. Centre, Department of Neurosurgery, All India Institute of Medical Sciences (AIIMS), New Delhi.
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Myelocystoceles, also known as syringoceles, syringomyeloceles, and lipomeningomyelocystoceles, represent 5% of all lumbosacral skin-covered masses. Terminal myelocystocele (TMC) is a rare variant of spinal dysraphism. At times, patients with TMCs can present with a huge lumbosacral mass (giant TMC). A 14-month-old female child presented with progressive increasing swelling in the lumbosacral region (35 cm × 35 cm × 30 cm) since birth with inability to move both lower limbs. Magnetic resonance imaging revealed a dilated terminal central canal herniating through a spina bifida defect (from L4 to S2) into a huge meningocele, suggestive of a giant TMC. The girl was operated on successfully and was doing well at 6 months follow-up, although neurologically unchanged. Giant TMC is a rare entity and only a few case reports are available in literature. Herein we present a case with TMC with the largest dimensions reported till date.
Keywords: Lumbosacral mass, spinal dysraphism, terminal myelocystocele
|How to cite this article:|
Varshney G, Gupta DK. Giant terminal myelocystocele: A case report. J Pediatr Neurosci 2020;15:286-9
| Introduction|| |
Myelocystocele is defined as closed spinal dysraphism with a localized, cystic dilatation of the central canal of the spinal cord herniated through a posterior spina bifida. Terminal myelocystoceles (TMC) represent 5% of all lumbosacral skin-covered masses. In TMC, there is dilatation of the terminal canal, which does not communicate with the subarachnoid space and is surrounded by a meningocele. These usually present as a lumbosacral mass with good skin cover, containing fat, cerebrospinal fluid (CSF), and neural tissue. Patients with TMC have normal intelligence. If not treated early, these patients can present with a huge lumbosacral mass (giant TMC), leading to cosmetic disfigurement and neurological sequelae from tethering of the cord.
| Case Report|| |
A 14-month-old female child was brought by her parents with a progressively increasing swelling over the lower back and weakness of both lower limbs since birth. There were no complaints of bowel or bladder incontinence. She weighed 15kg and her head circumference was 47 cm. There was no history of any CSF leak from the swelling and no prior history of hospital admission for meningitis. On examination, the girl was paraplegic (0/5 Medical Research Council [MRC]). The lumbosacral mass with a normal overlying skin was fluctuant and had a positive transillumination test and cough impulse. The swelling, which measured 45 cm × 40 cm × 35 cm, had obliterated the intergluteal cleft. Due to the huge mass, she was unable to sleep supine. Magnetic resonance imaging (MRI) revealed the classical imaging appearance of a TMC [Figure 1]. A dilated central canal (trumpet-like flaring) of the terminal cord had herniated into a giant meningocele through a spina bifida defect at L4-S2 level. Two separate sacs (sac within a sac appearance) could be seen distinctly on the MRI. There was no chiari, syrinx, or hydrocephalus on screening MRI of the brain and whole spine.
|Figure 1: (A) Sagittal T2W MRI showing TMC sac (green arrow) and meningocele sac (blue arrow) (sac within the sac appearance) herniating through spina bifida defect. (B) Trumpet-like flaring of the terminal spinal cord|
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Surgery was planned for this patient, keeping in mind that her neurological status was unlikely to improve after surgery but mere cosmetic repair and reduction in the size of the mass will allow for better care. The patient had to be induced and intubated in lateral position. To position the patient prone, about 6000mL of CSF was drained from swelling (the meningocele sac) percutaneously with a wide bore needle with simultaneous fluid replacement to prevent hemodynamic instability. Subsequently, the patient was positioned prone and a vertical incision was made. This opened up the meningocele sac and the inner sac (TMC) was clearly observed [Figure 2]. Myelocystocele was then opened and about 1500mL of clear CSF was drained. Continuation of the myelocystocele into the normal central canal cranially could be easily seen at surgery [Figure 2]. Pial sutures (neurulation) were taken with 8-0 nylon after excising the cyst wall. Primary dural reconstruction followed by multilayered closure of the incision was carried out. She was nursed in lateral position for 48h and received intravenous antibiotics for 24h post-surgery. Patient was discharged on postoperative day 5. On follow-up, sutures were removed on postoperative day 10. At 1 and 6 months follow-up, the patient was doing well, although she was neurologically unchanged.
|Figure 2: (A) Intraoperative photograph showing the myelocystocele sac (white arrow). The outer meningocele sac is also seen (red arrow). (B) Intraoperative photograph, after the myelocystocele sac (black arrow) has been opened. Continuity with the central canal is seen (yellow arrow)|
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| Discussion|| |
The most common skin-covered lumbosacral mass in a fetus is the lipomeningocele or lipoma, followed by the teratoma, hamartoma, and the other rarer tumors and mass lesions. Although similar in appearance on prenatal ultrasonography, it is important to distinguish TMC from myelomeningoceles, as the outcome and prognosis and thus the prenatal counselling will be quite different. The embryological origin of TMC has been debatable. McLone and Naidich postulated that the progressive dilatation of the terminal ventricle due to non-egress of CSF from the early neural tube disrupts the dorsal mesenchyme leading to the formation of spina bifida and eventually a myelocystocele. Later, Cohen proposed that forward eventration of posterior cloacal wall through the unsupported cloacal membrane pulls the notochord away from the secondary neural tube and somehow interrupts apoptosis. This was based on an observation that the tail gut, caudal notochord, and the cavitating medullary cord are adherent to each other during early secondary neurulation. Pang through his work on chick embryos proposed that TMC represents a frozen state of analogous (to chick embryo) stage in secondary neurulation resulting from lack apoptosis just before the planned dehiscence of terminal bubble from the cutaneous ectoderm. No nutritional deficiencies have been implicated but certain drugs such as loperamide, diphenylhydantoin, and retinoic acid have been associated with myelocystoceles.
TMC constitutes 4%–8% of lumbosacral occult spinal dysraphism., Epidemiologically, myelocystocele arises sporadically; there is no known familial incidence and no sex preponderance has been described. Skin overlying the lumbosacral mass is normal or may show hemangioma, nevus, or hypertrichosis., The intergluteal fold is commonly obscured and distorted by a myelocystocele. The diagnostic modality for myelocystocele is MRI. The most characteristic feature of TMC on MRI is a “trumpet-like” flaring of the distal central canal into an ependymal-lined terminal cyst. Screening the whole spine and brain is necessary to look for chiari, syrinx, and hydrocephalus, even though rarely associated with TMC. Muthukumar found the “target sign” as seen on coronal T2-weighted MRI, useful in delineating the hydromyelic cord. There were no other associated anomalies in our patient and no cutaneous stigmata were seen, a finding similar to other case report.,
TMC, if not treated early, can attain huge dimensions and can lead to development of neurological deficits or worsening of the existing deficits. The parents of our patient did not seek medical attention due to financial constraints. The patient was paraplegic at time of presentation. Patients with giant TMC, as described in other case reports,,,, also had motor deficits in lower limb but none of them were paraplegic. Neurological deficits were reported in 47% patients by Gupta in their series of 17 cases with TMC. Interestingly, Pang in their study of 10 patients with TMC (four newborns and six older children) found that all the newborns were neurologically normal, whereas all the older children had neurological deficits. Muthukumar noted that 10 of the 14 patients with TMC had some form of neurological deficits. Cohen found neurological deficits in all four patients in his study. Thus, early surgery is warranted for these patients. Surgery serves dual purpose of cosmesis and detethering of cord; in our patient, however, aim of surgery was purely cosmetic. Presence of this swelling and paraplegia prevented the patient from sitting on her own. She had to be constantly supported by either parent to maintain acceptable position for feeding and other purposes. The biggest challenge in the surgical management of our patient was positioning, not just for surgery but also for anesthetic induction. To overcome this, endotracheal intubation was performed in lateral position. After this we drained the meningocele, following which the surgery was completed.
| Conclusion|| |
TMC is a rare variety of spinal dysraphism. Giant TMCs are even rarer. Patients with giant TMC may have neurological deficits at presentation. Early surgery is recommended for cosmesis and detethering the cord. Our patient had a huge TMC with paraplegia, both of which were hindrances in day-to-day care of the patient. Surgery for patients with such a huge mass must be planned in detail, taking into account the difficulties with positioning the patient on operating table. By excising the giant mass and detethering the cord, we could at least ensure that her caregivers could take better care of her, even though there was no neurological improvement.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]