Superficial spreading malignant melanoma

Superficial spreading malignant melanoma is the most common form of cutaneous melanoma in Caucasians. The average age at diagnosis is in the fifth decade, and it tends to occur on sun-exposed skin, especially on the backs of males and lower limbs of females.

One-quarter to one-third of the time, this disease evolves from a precursor lesion, usually a dysplastic nevus.

The microscopic hallmarks are:

• Large melanocytic cells with nest formation along the dermo-epidermal junction.
• Invasion of the upper epidermis in a 'pagetoid' fashion (discohesive single cell growth).
• The pattern of rete ridges is often effaced.

External links

Fact File from the Royal College of Pathologists of Australasia (pdf) [1]