Dysplastic Nevus

Background

• A dysplastic nevus is a benign, pigmented, cutaneous lesion with histologic findings of architectural disorder and cellular atypia.
• The term "atypical nevus" is used to describe a pigmented nevus with color variegation, and irregular or indistinct borders seen on clinical exam, while the term "dysplastic nevus" incorporates the histologic diagnosis.
• Dysplastic nevi may undergo transformation to melanoma, and they may be associated with increased risk of melanoma at other sites, particularly in individuals with many nevi (> 50) or a family history of melanoma.

Evaluation

• Patients usually present with a "mole" or darkly pigmented lesion with irregular or indistinct borders and size ≥ 6 mm in diameter.
• Evaluate suspicious lesions according to ABCDE criteria as used for melanoma:
  • A - asymmetry
  • B - border irregularities
  • C - color variation (mottled, shades of brown, black, gray, and white)
  • D - diameter > 6 mm (pencil eraser)
  • E - evolving size, shape, surface (raised, bleeding, crusting), shades of color, or symptoms (itchiness, tenderness)
• Consider familial atypical multiple mole melanoma (FAMMM) syndrome in patients with > 50 nevi, including some atypical nevi, and personal or family history of melanoma.
• Consider dermoscopy for more detailed exam of lesions.
• Consider full-body photography for mapping in patients with multiple nevi.

Management

• For any lesion suspicious for melanoma, consider excisional biopsy with 1- to 3-mm clinical margins.
• Consider re-excision for positive margins on histopathology.
• For stable, atypical nevi with low suspicion of melanoma, consider monitoring with serial photographic imaging of lesions (including dermoscopic imaging) or total body photographs instead of diagnostic excision.
• For patients with familial atypical mole melanoma (FAMM) syndrome, consider genetic counseling and increased surveillance with dermoscopy and total body photography for early detection of lesions suspicious for melanoma.