Acral nevus

Acral nevus, also volar nevus, is a benign melanocytic lesion of the palm or sole.

Melanocytic nevus with intraepidermal ascent of cells (abbreviated MANIAC) redirects to here.

General

• Palms or soles.
• May be confused with malignant melanoma.

Note:

• Volar refers to the palmar aspect or plantar aspect.

Gross

• Pigmented lesion.

Note:

• Should be bisected perpendicular to the dermatoglyphs (ridges).
  • Lesions sectioned parallel to the ridges (on microscopy) may appear to have confluent junctional nests (leading to the diagnosis of melanoma).

Microscopic

Features:

• Acral skin:
  • Thick stratum corneum (hyperkeratotic).
  • Thick stratum spinosum (acanthotic).
• Nevus with intraepidermal ascent of cells.
  • May be referred to as Pagetoid scatter.
  • Should not be present at the edge of the lesion - key feature.

Notes:

• Intraepidermal ascent of cells is usually suggestive of melanoma.
  • In acral sites (esp. at the centre of a lesion) the criteria are relaxed, i.e. this is considered benign for this site.
• Nests in the ridges raise the suspicion of melanoma.
  • Memory device "ridges are risky, furrows are fine".

DDx:

• Acral lentiginous melanoma.

See also

• Melanocytic lesions.