Skin - Melanocytic tumor
Melanoma
Subungual melanoma

Author: Christopher Hale, M.D. (see Authors page)

Revised: 20 February 2017, last major update May 2013

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Subungual melanoma

Cite this page: Subungual melanoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumormelanocyticsubungualmelanoma.html. Accessed May 1st, 2017.
Definition / general
  • Melanoma arising in nail unit
Epidemiology
  • Uncommon; difficult to diagnose clinically and pathologically
  • Median age 66 years (Am J Surg 2008;195:244), range 24 to 83
Sites
  • Common sites are great toe and thumb
Clinical features
  • Often delay in diagnosis because lesion is attributed to trauma; most (73%) cases are AJCC stage II / III, acral lentiginous subtype (66%) and Clark level IV / V (79%, Am J Surg Pathol 2007;31:1902)
  • Sentinel node metastases in 24%
Case reports
Treatment
Dermoscopy
  • Useful for distinction from subungual hemorrhage
  • Features include: Hutchinson sign, longitudinal irregular lines, triangular shape of bands, vascular pattern and ulcerations (Br J Dermatol 2013;168:1224)
Clinical images

Images hosted on other servers:

Red, friable, broad-based nodule

Ulcer on left middle finger

Microscopic (histologic) description
  • Usually not circumscribed
  • Have prominent lentiginous growth with more single cells than nests, moderate to severe atypia, haphazard and dense pagetoid intradermal spread
  • Also ulceration (33%), tumor infiltrating lymphocytes
Microscopic (histologic) images

Images hosted on other servers:

Tumor cells are isolated or in nests

Tumor cells are MelanA+

Differential diagnosis