Superficial spreading melanoma

Superficial spreading melanoma
Other names	Superficially spreading melanoma [1]
Specialty	Dermatology

Superficial spreading melanoma (SSM) is a type of skin cancer that typically starts as an irregularly edged dark spot typically on sun-exposed part of the body. ^{[2] [3]} The colour may be variable with dark, light and reddish shades; occasionally no color at all. ^[2] It typically grows in diameter before spreading to deeper tissue, forming a bump or becoming an ulcer. ^[2] Itching, bleeding and crust formation may occur in some. ^[2] The backs and shoulders of males and legs of women are particularly prone. ^[2]

It is a type of melanocytic tumor occurring in intermittently sun-exposed skin. ^[2] The cause is associated with repeated sunburns in childhood, intermittent exposure to sun during life, and sun bed use. ^[2]

Two-thirds of cases occur in light skin, and it is less common in dark skin. ^[2]

The average age at diagnosis is in the fifth decade.^{[ citation needed ]}

Signs and symptoms

Often, this disease evolves from a precursor lesion, usually a dysplastic nevus. ^{[ citation needed ]} Otherwise it arises in previously normal skin. A prolonged radial growth phase, where the lesion remains thin, may eventually be followed by a vertical growth phase where the lesion becomes thick and nodular. As the risk of spread varies with the thickness, early SSM is more frequently cured than late nodular melanoma. ^{[ citation needed ]}

Histopathology

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.
• Invasion of the dermis by atypical, pleomorphic melanocytes
• Absence of the 'maturation' typical of naevus cells
• Mitoses

Treatment

Treatment is by excisional biopsy, wide local excision and possibly sentinel node biopsy. Localized melanoma, which has not spread beyond the skin, has a very good prognosis with low recurrence rates. Spread of disease to local lymph nodes or distant sites (typically brain, bone, skin and lung) marks a decidedly poor prognosis. ^{[ clarification needed ]}

See also

• Melanoma
• List of cutaneous conditions

References

1. James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN   0-7216-2921-0.
2. DE, Elder; D, Massi; RA, Scolyer; R, Willemze (2018). "2. Melanocytic tumours". WHO Classification of Skin Tumours. Vol. 11 (4th ed.). Lyon (France): World Health Organization. pp. 76–77. ISBN   978-92-832-2440-2.
3. "Superficial spreading melanoma | DermNet". dermnetnz.org. Retrieved 1 July 2023.

External links

• Fact File from the Royal College of Pathologists of Australasia (pdf)