Superficial spreading melanoma

Medical condition

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 less common in dark skin.[2]

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

## Signs and symptoms[edit]

Often, this disease evolves from a precursor lesion, usually a dysplastic nevus. 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.

## Histopathology[edit]

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[edit]

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.

## See also[edit]

* Melanoma
* List of cutaneous conditions

## References[edit]

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. ^ a b c d e f g h 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[edit]

Classification|

* ICD-10: C43 (ILDS C43.L20)
* ICD-O: M8743/3

|

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

* v
* t
* e

Skin cancer of nevi and melanomas

Melanoma|

* Mucosal melanoma
* Superficial spreading melanoma
* Nodular melanoma
* lentigo
* Lentigo maligna/Lentigo maligna melanoma
* Acral lentiginous melanoma
* Amelanotic melanoma
* Desmoplastic melanoma
* Melanoma with features of a Spitz nevus
* Melanoma with small nevus-like cells
* Polypoid melanoma
* Nevoid melanoma
* Melanocytic tumors of uncertain malignant potential

Nevus/
melanocytic nevus|

* Nevus of Ito/Nevus of Ota
* Spitz nevus
* Pigmented spindle cell nevus
* Halo nevus
* Pseudomelanoma

* Blue nevus
* of Jadassohn–Tièche
* Cellular
* Epithelioid
* Deep penetrating
* Amelanotic
* Malignant

* Congenital melanocytic nevus (Giant
* Medium-sized
* Small-sized)

* Balloon cell nevus
* Dysplastic nevus/Dysplastic nevus syndrome

* Acral nevus
* Becker's nevus
* Benign melanocytic nevus
* Nevus spilus

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