Melanoma pattern and structures on special sites
Volar: melanomas on the palms and soles
- Parallel ridge pattern
- Atypical fibrillar pattern
- Diffuse pigmentation with multiple shades of brown
- Multi-component pattern
- Annular-granular pattern
- Asymmetric follicular openings
- Gray dots/granules around ostial openings
- Circle within circle sign
- Angulated lines forming rhomboids
The presence of melanin inclusions defines the lesion as melanocytic. These lesions consist of melanocyte activation as seen in lentigo or melanocytic proliferation as seen in nevi and melanoma. While evaluating the nail plate it is important not to overlook evaluating the paronychia (micro-Hutchinson’s sign) area and hyponychial skin (parallel ridge pattern will be seen).
- Atypical bands
consisting of lines of different colors and thicknesses. The bands may lose their parallelism and appear to converge distally creating a triangular appearance to the band (wider at proximal end and narrow at the distal end)
The features to define early mucosal melanoma have not yet been elucidated. Clearly any lesion with a multi-component pattern should be viewed with suspicion. In addition, any lesion manifesting the colors blue, gray or white should be view with concern for melanoma.