Skin melanocytic tumor
Other pigmented lesions and disorders of pigmentation
Other pigmented lesions and disorders of pigmentation - General
Author: Christopher S. Hale, M.D.
Last author update: 1 March 2013
Last staff update: 3 November 2020
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Pigmented lesions disorders pigmentation general
Table of Contents
Definition / general | Patterns of Benign Behavior | Other Benign Features | Maturation | Case reportsCite this page: Hale C Other pigmented lesions and disorders of pigmentation - General. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticgeneralothermelanocytic.html. Accessed April 19th, 2024.
Definition / general
- Often only part of lesion is excised and pathologist report includes recommendation for complete excision (J Clin Pathol 2004;57:1121)
Patterns of Benign Behavior
- Lentiginous hyperplasia (single cell melanocytic growth along dermoepidermal junction)
- Nested proliferation
- Melanocyte nuclei are smaller than adjacent keratinocytes
- Pagetoid proliferation (discohesive single cell growth throughout entire epidermis) is nonspecific; present in Spitz nevi, acral nevi, melanoma (Am J Surg Pathol 1995;19:792)
Other Benign Features
- Symmetric pattern of growth and involution
- Lateral dimension of dermal component should roughly equal that of original epidermal component ("shoulder" = when epidermal component extends laterally beyond dermal)
Maturation
- Deeper portion of lesion has smaller cells with less pigment, less atypia
- Deep cells grow in smaller sized nests or single cells
- May resemble neural tissue
- Maturation is a morphologic term; does not truly reflective biologic maturation (Am J Dermatopathol 1988;10:20)
Case reports
- 7 month old girl with lentiginous hyperplasia associated with hamartoma (Am J Dermatopathol 2008;30:488)
- Lentiginous melanocytic hyperplasia overyling dermatofibroma (J Dermatol 1996;23:840)
