Skin melanocytic tumor
Superficial spreading melanoma

Topic Completed: 1 May 2013

Revised: 28 May 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Superficial spreading melanoma

Christopher S. Hale, M.D.
Page views in 2018: 4,829
Page views in 2019 to date: 4,586
Cite this page: Hale CS. Superficial spreading melanoma. website. Accessed October 21st, 2019.
Definition / general
  • Traditional considered most common type of melanoma (50 - 75%) but lentigo maligna may actually be more common in patients with extensive sun exposure (J Am Acad Dermatol 2008;58:1013)
  • Recently diagnosed tumors are thinner with less ulceration than in the past (Cancer 2008;113:3341)
  • Note: can be in situ or invasive

Risk factors:
  • Extensive sun exposure during childhood, family history of melanoma, large numbers of benign nevi and dysplastic nevi
  • Recommended to evaluate vertical growth phase as prognostic factor for thin (< 0.76 mm) tumors (Am J Surg Pathol 2003;27:717)
  • Usually affects light skinned individuals, young adults to elderly
  • Often trunk and extremities
Clinical features
  • Variegated, black, brown, tan, blue, pink or white
  • Slightly elevated, flat and irregular margins, often with an indentation or notch
  • May have white areas of tumor regression or nodular areas of deep dermal invasion
Case reports
  • Multicomponent pattern, asymmetry and multiple colors
  • Also atypical reticular pattern (irregular holes and thick lines) with a sharp demarcation, bluish white veil, irregular linear vessels, central ulceration and irregularly distributed dots
Clinical images

Images hosted on other servers:

Various images

Irregular black tumor with periumbilical elevation

Microscopic (histologic) description
  • Classified based on radial growth component (has nothing to do with level of dermal invasion)
  • Noninvasive areas have asymmetry and poor circumscription, irregular acanthosis, irregular lentiginous and nested proliferation, uniform atypical melanocytes with nests and pagetoid cells
  • Also transdermal migration, nuclear pleomorphism, dusty pigmentation, apoptosis of individual melanocytes and pigmented parakeratosis
  • A variant composed predominantly of large nests has been described (Mod Pathol 2012;25:838)
Microscopic (histologic) images

Images hosted on other servers:

Superficial spreading melanoma and satellite nodule

Beta catenin expression in primary

Positive stains
Molecular / cytogenetics description
Back to top