Superficial spreading melanoma
Template:Infobox medical condition (new) 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.[1][2] The colour may be variable with dark, light and reddish shades; occasionally no color at all.[1] It typically grows in diameter before spreading to deeper tissue, forming a bump or becoming an ulcer.[1] Itching, bleeding and crust formation may occur in some.[1] The backs and shoulders of males and legs of women are particularly prone.[1]
It is a type of melanocytic tumor occurring in intermittently sun-exposed skin.[1] The cause is associated with repeated sunburns in childhood, intermittent exposure to sun during life, and sun bed use.[1]
Two-thirds of cases occur in light skin, and it is less common in dark skin.[1]
The average age at diagnosis is in the fifth decade.Script error: No such module "Unsubst".
Signs and symptoms
Often, this disease evolves from a precursor lesion, usually a dysplastic nevus. Template:Source? 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. Template:Source?
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. Script error: No such module "Unsubst".
See also
References
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External links
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