Peer Reviewed

Photoclinic

Cervical Dermal Sinus Associated With Intradural Dermoid Cyst

Volume 61 - Issue 3 - March 2021

AUTHORS:
Aviva Jaari Whelan, MD1,2 • James N. Crooks, MD1,2

AFFILIATIONS:
1University of Illinois College of Medicine at Peoria, Illinois
2OSF HealthCare Children’s Hospital of Illinois, Peoria, Illinois

CITATION:
Whelan AJ, Crooks JN. Cervical dermal sinus associated with intradural dermoid cyst. Consultant. 2021;61(3):e18-e19. doi:10.25270/con.2020.07.00010

Received April 7, 2020. Accepted June 29, 2020. Published online July 30, 2020.

DISCLOSURES:
The authors report no relevant financial relationships.

CORRESPONDENCE:
James N. Crooks, MD, Department of Pediatrics, OSF HealthCare Children’s Hospital of Illinois, 530 NE Glen Oak Ave, Peoria IL 61637 (jcrooks2@uic.edu)

 

A 12-month-old boy presented as an outpatient to a pediatrician with concern for a posterior cervical dimple.

Two weeks prior to admission at our institution, the patient had been discharged from a pediatric intensive care unit (PICU) in Mexico, where he had been admitted for hemiparesis and status epilepticus secondary to bacterial meningitis. At that time, purulent fluid was noted to have been draining from the cervical dimple. The patient had received approximately 2 months of intravenous antibiotics to treat the meningitis, which had led to improvement of his neurologic deficits. Following treatment, he had been referred to a neurosurgeon in Mexico to correct the malformation; however, the family traveled to the United States for continued care.

After evaluation by the outpatient pediatrician, the patient was admitted to a children’s hospital for further evaluation. At presentation, the patient was well appearing, playful, and active. Vital signs were within normal limits. Physical examination findings were remarkable for a small cervical dimple measuring approximately 2 to 3 mm, at the level of C3, with what appeared to be an easily visualized base. There were no abnormal skin findings surrounding the lesion. His only neurological deficits were mild gross motor delays.

After neurosurgical consultation, magnetic resonance imaging (MRI) of the spine was performed, the results of which revealed a dermal sinus tracking into the spinal canal, with a ring-enhancing lesion (Figure).

MRI scan
Figure. MRI of the spine revealed a dermal sinus tracking into the spinal canal through C2-C3 and communicating with a peripherally enhancing dermoid cyst.

According to the radiology report, MRI showed a “small cutaneous pit with a linear/tubular dermal sinus tract traversing a probable defect within the posterior arch of C2 …, communicating with an intradural/extramedullary … peripherally enhancing mass along the dorsal aspect of the cord.” The neurosurgery team scheduled the patient for surgery within 1 week to close the congenital dermal sinus and remove the dermoid cyst.

The patient underwent an elective excision of the cervical dermal sinus with C2 laminectomy without complications, and he was admitted to the PICU following surgery. He subsequently was discharged home the following day. Pathology test results revealed an inflamed dermoid cyst. Approximately 10 months after surgery, the patient did not have any apparent deficits or postsurgical complications.

DISCUSSION

Congenital dermal sinuses are believed to form when the neuroectoderm and cutaneous ectoderm fail to separate during neurulation.1-6 It is important to note that dermal sinuses can extend to varying depths and do not always penetrate the dura and enter the central nervous system (CNS), where they often present with the most serious complications.1

The reported overall prevalence of dermal sinuses is approximately 1 in 2500 live births1-3,7; however, Ackerman and Menezes2 and Radmanesh and colleagues3 question the accuracy of this rate, considering the methods used in previous studies and the concern that coccygeal pits may have been included in the data. Coccygeal pits are distinctly different from dermal sinuses and may occur at rates as high as 4% in the general population.2 Coccygeal pits lie between the gluteal clefts, are oriented caudally, and typically do not have a deeper pathology, whereas dermal sinuses lie superior to the gluteal clefts, are oriented cephalically,2,7 and in an estimated 50% of cases are associated with a dermoid or epidermoid tumor.3 Historical studies by McIntosh and colleagues8 (published in 1954) and Powell and colleagues5 (published in 1975) are commonly cited regarding the incidence and prevalence of dermal sinuses; however, both studies appear to have several flaws, most notably the lack of verification methods (such as magnetic resonance imaging or surgery) to determine whether physical examination findings represented true dermal sinuses. This suggests that the true incidence is lower, and that dermal sinuses may be much rarer than reported.

Dermal sinuses are more commonly seen in the lumbosacral region, followed by the occipital region.1,2,4-6 Less common locations are the thoracic and cervical areas of the spine, which are estimated to represent approximately 10% and 1% of dermal sinuses, respectively.6,7,9 Radmanesh and colleagues3 estimate that cervical dermal sinuses may make up less than 1% of cases. The cervical region is believed to be the least common location because fusion of the neural tube begins in the cervical region and proceeds both cephalically and caudally.1,9 In fact, Ackerman et al7 performed a review of the world literature in 2002 and found only 18 cases of cervical dermal sinuses.

Typically, dermal sinuses that enter the CNS present prior to 5 years of age,1,9 but more importantly, they present with severe neurologic or infectious complications.1-4 A number of neurologic complications have been reported including gait disturbances, extremity weakness, increased deep tendon reflexes, hemiparesis, and head deviation. These findings are typically a result of spinal cord compression by a dermoid cyst.1,4 Infectious complications include meningitis and intramedullary spinal cord abscesses, the latter of which have a high rate of association with dermal sinuses.6 In typical dermal sinus cases, it is recommended to have the lesion prophylactically resected. This improves morbidity and mortality by avoiding the potentially severe complications.1,6,9,10

It is common for dermal sinuses to also present with other types of spinal cord malformations such as tethered cord or split cord malformations, and the co-occurrence may be as high as 40%.3 Dermal sinuses are often associated with superficial cutaneous findings such as hemangiomas, telangiectasias, and tufts of hair, as well.1,2,10 The authors of one review of sacral dimples recommended that further investigation be performed in cases with multiple dimples, subcutaneous masses surrounding a dimple, a caudal appendage, a deviated or duplicated gluteal cleft, a dimple larger than 5 mm, a location 2.5 cm or more superior to the anal verge, or any superficial cutaneous findings.10

It is important for clinicians to be able to recognize the signs of a dermal sinus so that it can be evaluated prior to the occurrence of complications. It common for these lesions to present with an abnormality of the surrounding skin, but they also may appear without any other findings, and in some cases the dimple has a visualized base. Failure to have these lesions resected often leads to complications due to infection, such as meningitis or an intramedullary spinal cord abscess, or focal neurologic symptoms due to compression of the spinal cord.

REFERENCES:

  1. Lee J-K, Kim J-H, Kim J-S, et al. Cervical dermal sinus associated with dermoid cyst. Childs Nerv Syst. 2001;17(8):491-493. doi:10.1007/s003810000433
  2. Ackerman LL, Menezes AH. Spinal congenital dermal sinuses: a 30-year experience. Pediatrics. 2003;112(3 pt 1):641-647. doi:10.1542/peds.112.3.641
  3. Radmanesh F, Nejat F, El Khashab M. Dermal sinus tract of the spine. Childs Nerv Syst. 2010;26(3):349-357. doi:10.1007/s00381-009-0962-z
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  7. Ackerman LL, Menezes AH, Follett KA. Cervical and thoracic dermal sinus tracts: a case series and review of the literature. Pediatr Neurosurg. 2002;37(3):137-147. doi:10.1159/000064399
  8. McIntosh R, Merritt KK, Richards MR, Samuels MH, Bellows MT. The incidence of congenital malformations: a study of 5,964 pregnancies. Pediatrics. 1954;14(5):505-522.
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  10. Zywicke HA, Rozzelle CJ. Sacral dimples. Pediatr Rev. 2011;32(3):109-151. doi:10.1542/pir.32-3-109