Skin melanocytic tumor
Lentigines, melanotic macules and melanocytic hyperplasia
Melanocytic hyperplasia


Topic Completed: 1 March 2013

Revised: 10 May 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: atypical melanocytic hyperplasia

Christopher S. Hale, M.D.
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Cite this page: Hale C. Melanocytic hyperplasia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumormelanocyticatypicalmelanocytichyperplasia.html. Accessed August 19th, 2019.
Definition / general
Terminology
  • Also called atypical melanocytic proliferation or benign atypical junctional melanocytic hyperplasia
Case reports
Microscopic (histologic) description
  • Atypical single unit melanocytes limited to epidermis, often seen at periphery of classic melanoma
  • In contrast to melanoma in situ, exhibits only focal confluence at dermoepidermal junction, has limited pagetoid spread and involves only upper hair follicle
  • Factors favoring atypical melanocytic hyperplasia over melanoma in situ (Mod Pathol 2000;13:857):
    • No lateral spread
    • No upward extension into epidermis
    • No finely granular, "smoky" melanin
    • No marked cytologic atypia
    • No mitotic figures
    • No host inflammatory fibrotic response
Differential diagnosis
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