Skin - Nonmelanocytic tumors
Benign (nonmelanotic) epidermal tumors or tumor-like lesions
Large cell acanthoma

Author: Hillary Elwood, M.D. (see Authors page)

Revised: 3 October 2016, last major update July 2015

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Large cell acanthoma [title] skin

Cite this page: Large cell acanthoma. website. Accessed November 12th, 2018.
Definition / general
  • Benign intraepidermal lesion composed of large keratinocytes
  • Debate as to whether this represents a distinct entity or a reaction pattern within a solar lentigo (Int J Dermatol 2003;42:36)
  • Recent study suggests large cell acanthoma is a solar lentigo with cellular hypertrophy (J Cutan Pathol 2014;41:733)
Case reports
Gross description
  • Light-tan to dark brown, well circumscribed macule or patch
  • Few millimeters to centimeters in diameter
  • Typically on sun exposed skin
  • Clinically resembles a seborrheic or actinic keratosis
Microscopic (histologic) description
  • Atrophic or acanthotic epidermis containing larger than usual keratinocytes (~2x normal epidermal keratinocytes)
  • Usually well demarcated from adjacent epidermis
  • Basal layer may appear hyperpigmented; sometimes conspicuous rete ridges
  • Orthokeratosis; may have hypergranulosis
  • Minimal nuclear pleomorphism
  • Basal mitoses only
Microscopic (histologic) images

Images hosted on other servers:


Large keratinocytes, hyperkeratosis

Differential diagnosis