Dermal scar

Dermal scar
Diagnosis in short
Dermal scar. H&E stain.
LM	dense collagen - fibers run parallel to the DE junction, loss of dermal papilla, loss of adnexal structures, thin-wall blood vessels
LM DDx	malignant melanoma desmoplastic-neurotropic type, dermatofibroma, desmoplastic Spitz nevus, sclerosing blue nevus
Stains	S-100 -ve (mostly)
Site	skin
Clinical history	trauma, previous excision or biopsy
Prevalence	common
Prognosis	benign

Dermal scar
External resources
EHVSC	10187 (Dermal scar adjacent to a basal cell carcinoma)
Wikipedia	Scar

Dermal scar, also simply scar, is commonly seen in dermatopathology. It is also known a cicatrix.

General

• Previous surgery, biopsy, trauma.

Gross

• Raised irregularity - may be linear.
• Typically pale.
  • May be hyperpigmented.

Images

• 

  Scars. (WC)

Microscopic

Features:

• Loss of dermal papilla.
• Dense collagen - fibers run parallel to the dermal-epidermal (DE) junction - key feature.
• Loss of adnexal structures.

Other feature:

• Thin-walled blood vessels.
  • Described as running perpendicular to the surface - this may not be apparent.

Note:

• There should not be any nuclear hyperchromasia or pleomorphism.

DDx:

• Malignant melanoma, desmoplastic-neurotropic type - nuclear pleomorphism and/or hyperchromasia; may be focal.
  • Epidermal hyperplasia and the preservation of adnexal structures is very suspicious.
• Dermatofibroma.
• Desmoplastic Spitz nevus.
• Sclerosing blue nevus.

Image

• 

  Scar. (WC)

IHC

• S100 focal/scattered +ve.
  • Desmoplastic melanoma strong +ve.
• HMB-45 -ve.
  • Sclerosing blue nevus +ve.

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SKIN, LOWER MID BACK, RE-EXCISION:
- DERMAL SCAR.
- SOLAR ELASTOSIS.

Micro

The sections show skin with a dermis with dense collagen fibres that run parallel to the skin surface without adnexal structures. The overlying dermal-epidermis interface lacks the typical undulation.

See also

• Non-malignant skin disease.
• Dermatopathology.