Dorsal dermal sinus

Dr Dalia Ibrahim and Radswiki et al.

Dorsal dermal sinus (DDS) is an epithelium-lined tract from the skin to the spinal cord, cauda equina, or arachnoid.

Dorsal dermal sinus is caused by incomplete separation of the superficial ectoderm from the neural ectoderm, resulting in a focal segmental adhesion.

Later during embryogenesis, the spinal cord ascends relative to the spinal canal and stretches the adhesion into a long, tubular tract.

Dorsal dermal sinus manifests as a small dimple or pinpoint ostium, which is often associated with an area of hyperpigmented, angiomatous skin or hypertrichosis and occurs in a midline location or rarely in a paramedian location.

Soft-tissue asymmetry and bone anomalies are common findings.

Predominantly located in the lumbosacral region and less often in the occipital region.

Dorsal dermal sinus occurring in a paramedian location is often associated with an intraspinal dermoid or epidermoid, which causes compression of neural structures with neurologic symptoms.

  • ultrasound can show the entire length of the tract from the skin to the spinal cord
  • the tract can be difficult to identify within the subcutaneous fat
  • the tract is clearly demonstrated in the anechoic, cerebrospinal fluid–filled subarachnoid space as an echogenic structure

Typical complications are infections such as recurrent meningitis, epidural or subdural abscess, and intramedullary spinal cord abscess.

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Article information

rID: 12521
Synonyms or Alternate Spellings:
  • Dorsal dermal sinus (DDS)
  • Spinal dermal sinus

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Cases and figures

  • Figure 1: skin tag
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  • Case 1: dermal sinus reaching spinal cord
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  • Case 2: with diastematomyelia
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  • Case 3: with superficial cyst
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