Symptomatic cervical lipomyelomeningocele in an adult: illustrative case

Abstract

BACKGROUND

Cervical lipomyelomeningocele (LMMC) is an exceedingly rare form of spina bifida occulta. Cervical LMMC presenting in adulthood, particularly in the 4th decade, as cervical tethered cord syndrome is extremely uncommon.

OBSERVATIONS

The authors report the case of a woman in her early 40s who presented with clinical features of cervical compressive myelopathy. Neuroradiological evaluation showed cervical LMMC extending from C3 to C6, along with significant compression and flattening of the spinal cord. The patient underwent C3–6 laminectomy and excision of the lipomatous tissue, along with untethering of the cervical spinal cord under intraoperative neuromonitoring (IONM). Histopathological examination confirmed lipomatous tissue. Postoperatively, the patient demonstrated clinical improvement in spasticity and extremity weakness. Follow-up imaging showed satisfactory decompression and expansion of the cervical spinal cord.

LESSONS

Symptomatic cervical LMMC in adults is exceedingly rare. While asymptomatic cases may be managed conservatively with regular surveillance, excision of the lipoma with cord untethering remains the treatment of choice in symptomatic patients. The use of IONM provides an important safeguard during resection, minimizing neurological morbidity.

https://thejns.org/doi/10.3171/CASE25771

Spinal dysraphism represents a spectrum of congenital malformations involving the spine and the spinal cord, resulting from incomplete formation of the dorsal midline structures during embryogenesis.¹ The mildest form of spinal dysraphism is spina bifida occulta (closed spinal dysraphism), and the most severe form is spina bifida aperta (open spinal dysraphism), with an estimated incidence of 3–6 per 100,000 live births.²

Lipomyelomeningocele (LMMC) is the most common congenital cause of tethered cord syndrome, commonly involving the lumbosacral spinal levels.³ It is characterized by a subcutaneous lipoma attached to the dorsum of the spinal cord, along with herniation of the meninges and spinal cord through a defect in the fascia and bony lamina. The cervical involvement of LMMC is exceedingly rare, with only a few case reports published in the literature.⁴

Here, we report a rare case of cervical LMMC presenting with adult-onset cervical compressive myelopathy, which was successfully managed surgically at our center.

Illustrative Case

A 43-year-old female presented with a 6-month history of neck pain and paresthesia involving all four limbs. She also reported difficulty holding objects with both hands, unsteady gait, and frequent slippage of her footwear. The skin over the nape of the neck was normal, with no cutaneous stigmata of spinal dysraphism. Neurological examination revealed spasticity with 4+/5 power in all four limbs, hyperreflexia (deep tendon reflexes 3+), and bilateral extensor plantar responses. Sensory examination was grossly normal.

MRI of the cervical spine demonstrated a well-defined, lobulated lesion measuring 29 × 16 mm, which appeared hyperintense on both T1- and T2-weighted sequences, hypointense on T2 fat-suppressed images, and showed no gadolinium contrast enhancement. The lesion extended from the spinal canal into the posterior midline soft tissue at C3–6, resulting in effacement of the thecal sac and compression with flattening of the spinal cord from C3 to C6 (Fig. 1). CT of the cervical spine demonstrated C3–4 block vertebrae, spina bifida involving levels C2–5, and assimilation of the posterior arch of C1 (Fig. 1).

FIG. 1.

Preoperative images. A:T1-weighted MR image. The arrow indicates the lesion compressing the cervical spine. B:T2-weighted MR image showing a hyperintense lesion (arrow). C: T2 fat-suppressed MR image showing a hypointense lesion (arrow) at the cervical level. D: CT scans of the cervical spine showing spina bifida involving C2–5. The arrow indicates the bifida lamina.

The patient underwent C3–6 laminectomy and near-total excision of the lesion. A midline posterior cervical incision was made from the C2–7 level, followed by a C3–6 laminectomy. Intraoperatively, lipomatous tissue was noted protruding through a dural defect measuring approximately 25 × 10 mm. The normal dura cranial and caudal to the lesion was identified, and a durotomy was performed to visualize the proximal and distal normal cervical spinal cord (Fig. 2). The lipoma was excised using microscissors and an ultrasonic aspirator under intraoperative neuromonitoring (IONM) with bipolar and monopolar stimulation, resulting in successful untethering of the cervical spinal cord. After securing hemostasis, the dura was closed using nonabsorbable sutures, and a dural substitute (DuraGen, Integra Lifesciences) was placed to reinforce the residual dural defect (Video 1).

FIG. 2.

Left:Intraoperative image showing an LLMC (A) and normal dura distal to the lesion (B). Right: Intraoperative image showing the neural placode after excision of the lipoma (C) and retracted normal dural margins (D).

VIDEO 1. Operative video showing near-total excision of a cervical LMMC. Click here to view.

IONM was performed using somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs). A transient 30% reduction in amplitude of MEPs was observed during lipoma excision using an ultrasonic aspirator, which recovered after a brief pause; SSEPs remained stable throughout the surgical procedure. Histopathological examination showed a cystic lesion lined by meningothelial cells, with underlying mature adipose tissue and a few nerve bundles (Fig. 3). The postoperative course was uneventful, with no new neurological deficits, and the patient was discharged in stable condition.

FIG. 3.

Histopathological analysis of the LMMC. Hematoxylin and eosin stains (original magnification ×40 [A] and ×100 [B]) showing a cystic lesion lined by meningothelial cells, with underlying mature adipose tissue and a few nerve bundles. The arrows indicate psammoma bodies.

Follow-up MRI demonstrated uniform expansion of the cervical cord with near-total excision of the lipoma (Fig. 4). At the 3-month follow-up, the patient showed clinical improvement with reduced spasticity and improved gait.

FIG. 4.

Postoperative T1-weighted (A) and T2-weighted (B) MR images showing near-total excision of the lesion with postoperative changes.

Informed Consent

The necessary informed consent was obtained in this study.

Discussion

Observations

LMMC is a closed spinal dysraphism characterized by defective primary neurulation and premature disjunction, resulting in a neural placode–lipoma interface that lies outside the spinal canal. Tethered cord syndrome is a sequela of the lipomatous attachment to the spinal cord, resulting in the tethering of the spinal cord to the adjacent dura and the lipoma. LMMC may also be associated with syringomyelia, Chiari malformation, split cord malformation, dermal sinus, scoliosis, extremity deformity, and sacral dysgenesis.

The risk factors for the development of LMMC include maternal obesity and infants born to younger and older mothers. Unlike open neural tube defects such as myelomeningocele, folic acid fortification does not appear to reduce the risk of LMMC, suggesting a distinct pathogenetic mechanism.⁵ The likely pathogenic mechanism explaining tethered cord syndrome involves hypoperfusion of the tethered segment, leading to cord ischemia and mechanical stress on the stretched cord. The tethering of the spinal cord results in impaired mitochondrial oxidative metabolism in the affected segment, leading to various symptoms that are likely reversible on detethering the cord.⁶

The clinical presentation of tethered cord syndrome due to LMMC is similar in adults and children.⁷ The cutaneous stigmata associated with LMMC include swelling over the back, a tuft of hair, a dermal sinus, a rudimentary tail, and capillary hemangioma. The clinical manifestations of cord tethering include pain, gait disturbances, extremity weakness, sensory deficits, urinary incontinence, scoliosis, and various orthopedic deformities in the extremities. The onset of the clinical symptoms is usually insidious, but the risk factors associated with a sudden onset and rapid decline include trauma, obesity, pregnancy, and strenuous activity. Radiological evaluation by MRI of the spine is essential to determine the location of the LMMC, as well as the presence of associated anomalies, including a low-lying tethered cord. MRI of the brain is performed to look for hydrocephalus. CT imaging of the spine is performed before surgical management to assess the bony anatomy, as well as any associated scoliotic deformity.⁸

There are no established guidelines for the management of cervical LMMC due to the rarity of the lesion. There is a debate regarding early surgical management for asymptomatic patients with LMMC. A few studies have preferred early surgical intervention, whereas others have preferred close observation with conservative management. Symptomatic patients with LMMC require surgical intervention. The principles of surgical management of LMMC include detethering of the cord, which involves excising the lipoma, preserving the neural tissue, and preventing retethering. Various techniques to prevent retethering include meticulous excision of lipomatous tissue, pial reconstruction sutures, and expansile duroplasty with redundant dural graft.⁹

Gürkanlar and Gonul reported on a 22-year-old male presenting with asymptomatic posterior cervical swelling without neurological involvement managed by excision without any complications.⁴ Heidari et al. described a 10-year-old female with congenital cervical swelling who later developed right upper limb weakness that improved after laminectomy, lipoma excision, and cord untethering, with IONM demonstrating improved MEPs after untethering.³ Abu-Bonsrah et al. reported cervicothoracic LMMC in a 19-year-old female complaining of neck pain, swelling in her back, and left lower limb weakness.⁷ She underwent multiple surgeries involving laminectomy and excision of the lipomatous tissue, along with untethering of the cord, before neurological stabilization.⁷ Sheih and Lam reported a case of anterolateral cervical LMMC with multiple congenital anomalies in a 1-day-old neonate requiring staged surgical management (Table 1).¹⁰

TABLE 1.

Summary of cervical LMMC cases

Case No.	Authors & Year	Age/Sex	Level	Diagnosis	Neurological Evaluation	Surgical Procedure
1	Gürkanlar & Gonul, 20074	22 yrs/M	C6	Cervical LMMC	Normal	Excision
2	Heidari et al., 20203	10 yrs/F	C7	Cervical LMMC	Rt upper limb weakness	C6–7 laminectomy, excision of lipoma, untethering
3	Abu-Bonsrah et al., 20167	19 yrs/F	C6–D6	Cervicothoracic LMMC	Neck pain, lt lower limb weakness	Laminectomy, excision of lipoma, untethering
4	Shieh & Lam, 200610	1 day/M	C3	Anterolat cervical LMMC	Rt upper limb weakness	Anterior cervical fusion & posterior cervical fusion
5	Present case	43 yrs/F	C3–6	Cervical LMMC	Spastic quadriparesis	C3–6 laminectomy, excision of lipoma, untethering

D = dorsal.

IONM has become an important adjunct in the surgical management of LMMC, helping balance safe resection with maximal functional preservation.¹¹ IONM consists of various techniques such as SSEPs, MEPs, D-waves, and neuroelectromyography. The intraoperative warning criteria for SSEPs are a reduction in signal amplitude by 50% or a 10% prolongation of latency from baseline. The similar warning criteria for MEPs include a threshold elevation of ≥ 100 V, along with changes in the waveforms to biphasic short-duration potentials and a 50% reduction in the amplitude. In case of a fall in the amplitude of MEPs, one must rule out the reversible causes, including hypothermia, hypotension, and high-dose propofol usage.¹² Neurological recovery after surgery is more consistently seen in sensorimotor deficits than in preexisting urodynamic dysfunction.³

The present case is distinctive because of the unusually late presentation at 43 years of age—the oldest reported to date in the existing literature. Cervical LMMC with symptomatic presentation in this age group is a diagnostic surprise. Unlike most cases diagnosed in childhood or early adulthood, our patient remained asymptomatic until the onset of neck pain and progressive spastic quadriparesis. Surgical management with lipoma excision and cord untethering under IONM guidance resulted in sustained neurological improvement at the 2-year follow-up, underscoring the value of timely surgical intervention even in older patients.

Lessons

Cervical LMMC is an exceptionally rare congenital anomaly, with very few cases reported in adulthood. A radiological diagnosis of cervical LMMC in a 43-year-old woman presenting with cervical myelopathy without any neck swelling or cutaneous stigmata is particularly unusual. In view of the rarity of the cervical location for LMMC, management guidelines have not been defined. While asymptomatic cases can be managed by regular follow-up, symptomatic cases warrant excision of the lipoma with untethering of the spinal cord. Excision of a cervical LMMC is a safe and effective procedure, offering substantial clinical improvement without added neurological morbidity when performed using IONM as an adjunct tool.

Acknowledgments

We thank Mrs. Sravani Lingam for her contribution to the manuscript preparation.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Yerragunta, Bethanbhatla, Sahoo, Kanala. Acquisition of data: Yerragunta, Bethanbhatla, Sahoo, Kanala, Pasham, Bhattacharjee. Analysis and interpretation of data: Yerragunta, Bethanbhatla, Sahoo, Kanala, Pasham, Bhattacharjee. Drafting the article: Yerragunta, Bethanbhatla, Sahoo, Kanala, Pasham. Critically revising the article: Yerragunta, Bethanbhatla, Kanala, Rangan, Pasham, Bhattacharjee. Reviewed submitted version of manuscript: Yerragunta, Bethanbhatla, Kanala, Rangan. Approved the final version of the manuscript on behalf of all authors: Yerragunta. Statistical analysis: Yerragunta, Bethanbhatla, Kanala. Administrative/technical/material support: Yerragunta, Bethanbhatla, Sahoo, Kanala. Study supervision: Yerragunta, Bethanbhatla, Kanala.

Supplemental Information

Videos

  Video 1. https://vimeo.com/1174037534.

Correspondence

Thirumal Yerragunta: Nizams Institute of Medical Sciences, Hyderabad, Telangana, India. drtirumal@gmail.com.