Skin melanocytic tumor
Topics to be merged
Junctional nevus
Author: Christopher S. Hale, M.D.
Topic Completed: 1 February 2017
Minor changes: 22 September 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Junctional nevus [title]
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Case reports | Treatment | Dermoscopy | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Hale CS. Junctional nevus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticJunctnevus.html. Accessed March 4th, 2021.
Definition / general
- Melanocytic proliferation restricted to basal epidermis (junctional area)
- Earliest stage of intraepidermal melanocytic proliferation
Terminology
- Lentigo simplex:
- Also called lentigo, lentigines
- Often in acral sites
- Precursor lesion to nevi, with proliferation of melanocytes (but no nests) in epidermal basal layer along rete ridges (DermNet NZ)
- Multiple lentigines:
- Associated with Peutz-Jeghers syndrome, centrofacial lentiginosis, Moynahan’s syndrome, LEOPARD syndrome, Carney’s syndrome and xeroderma pigmentosum
Epidemiology
- Traditionally considered more common in children (possible sampling bias), may actually occur in all ages (J Am Acad Dermatol 2007;56:825)
- Melanomas may arise from junctional nevi
Sites
- Usually non-sun exposed areas, such as palms and soles (J Am Acad Dermatol 2007;56:825)
Clinical features
- Small, flat or slightly elevated; non-hairy, deeply pigmented
Case reports
- 57 year old woman with coexisting mastocytoma (Am J Dermatopathol 2004;26:478)
Treatment
- None needed; excision for cosmetic reasons, laser for flat lesions (Br J Dermatol 2003;148:80)
Dermoscopy
- Regular pigmented network of brown and uniform color, more prominent in center with gradual fading to borders (reticular pattern)
- May have black or brown globules and dots regularly distributed inside lesion (usually in central region)
Microscopic (histologic) description
- Rounded nests of melanocytes / nevus cells on epidermal side of dermoepidermal junction, originating from tips of rete ridges
- Variable lentiginous melanocytic hyperplasia
Microscopic (histologic) images
Contributed by Mark R. Wick, M.D.
Breast skin
