superficial spreading melanoma


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su·per·fi·cial spread·ing mel·a·no·ma

primary cutaneous melanoma characterized by intraepidermal growth extending laterally beyond the site of dermal invasion.

superficial spreading melanoma

the most common melanoma that grows outward, spreading over the surface of the affected organ or tissue. It occurs most commonly on the lower legs of women and the torso of men. The lesion is raised and palpable, unevenly pigmented, and irregularly shaped and has an unclear border. See also lentigo maligna melanoma, nodular melanoma.
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Superficial spreading melanoma

superficial spreading melanoma

Dermatology A melanoma, 70% of which affect Pts from age 30 to 60, especially ♀ in lower legs or trunk, as a flat lesion–radial growth phase that may be present for months to yrs, average 5-yr survival 75% Etiology Recreational suntanning. See Melanoma.

superficial spreading melanoma

large, flat, irregularly pigmented skin lesion; tends to spread laterally, rather than invading at its deep margins; characteristically presenting in Caucasians on the skin of the back (in male) and lower leg (in females) (see Table 1)
Table 1: Clinical features of presentations of malignant skin lesions
LesionClinical features
Lentigo malignant melanomaSlow-growing flat lesion, often affecting facial skin in the elderly
Irregular border, slowly extending
Variegated colour
May develop nodular centre, ulcerate and spread aggressively
Superficial spreading melanomaMay affect any skin area, especially in Caucasians (male back, female leg)
Irregular raised border, slowly extending
Central area may become pale and appear to 'resolve' (which designates that the lesion is invading underlying tissues)
Nodular melanomaMay affect any skin, but especially the lower limbs and trunk
Many lesions are amelanotic ± pigmented collar
Grows rapidly and bleeds easily
May be misdiagnosed as a vascular lesion
Acral lentiginous melanomaTends to present in black and oriental skin
Presents initially as a flat freckle-like lesion that extends and becomes nodular
Often underdiagnosed
Subungual melanomaMelanoma involving the nail unit
May be difficult to distinguish from benign melonychia or subungual haematoma
Tends to affect proximal nail area and eponychium, and spreads distally
References in periodicals archive ?
3-8,16) Historically, three main subtypes of melanoma including superficial spreading melanoma (SSM), lentigo maligna melanoma (LMM) and nodular melanoma (NM) were first described in 1969; (9) desmoplastic melanoma (DM) was added in 1971; (12) and acral lentiginous melanoma (ALM) was introduced in 197710 and defined in 1980.
NM = nodular melanoma, LMM = lentigo maligna melanoma, SSM = superficial spreading melanoma, ALM = acral lentiginous melanoma, DM = desmoplastic melanoma.
Recently, epidemiologic analysis led to the proposal of an "early-onset melanoma" category, which is predominantly associated with female sex, superficial spreading melanoma, and a lower extremity location, and a "late-onset melanoma" category, which is predominantly associated with male sex, lentigo maligna melanoma, and a head and neck location.
The histologic profile of superficial spreading melanoma consists of an asymmetric proliferation of uniformly atypical melanocytes that are found at all levels of the epidermis, with single or small aggregates of atypical melanocytes present in the stratum corneum or granulosum ("pagetoid growth").
The unique clinical and histologic features discussed above and summarized in Table 2 suggest that lentiginous melanoma represents a distinct clinicopathologic entity from a common lentiginous nevus, dysplastic nevus, superficial spreading melanoma, and lentigo maligna.
For example, superficial spreading melanomas, by definition, demonstrate prominent radial growth and have a better prognosis than nodular melanomas, which predominantly demonstrate vertical growth.
Relevance of vertical growth pattern in thin level II cutaneous superficial spreading melanomas.
In superficial spreading melanoma, the intraepidermal growth phase is generally of shorter duration than in lentigo maligna melanoma.
Changes in the presentation of nodular and superficial spreading melanomas over 35 years.
Although 70% of melanomas in adults are sun induced, superficial spreading melanomas, about 80% in children arise from congenital nevi or de novo nodular lesions, he said.
Pan-nuclear staining is also observed in a subset of neoplastic cells in superficial spreading melanomas and nodular melanomas, but not to the extent seen in the setting of lentiginous melanomas.

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