Skin melanocytic tumor
Topics to be merged
Lentiginous melanoma
Author: Christopher S. Hale, M.D.
Topic Completed: 1 May 2013
Minor changes: 22 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Lentiginous melanoma
Table of Contents
Definition / general | Epidemiology | Sites | Microscopic (histologic) description | Differential diagnosisCite this page: Hale CS. Lentiginous melanoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticlentiginousmelanoma.html. Accessed March 5th, 2021.
Definition / general
- Rare subset of slowly progressing, radial growth phase melanoma with lentiginous proliferation of moderately atypical epithelioid melanocytes, focal pagetoid spread and nesting; not associated with architectural changes at dermoepidermal junction (Arch Pathol Lab Med 2011;135:337)
- First described in 2005 (Mod Pathol 2005;18:1397)
- May remain in situ for prolonged periods before invasion
- May be an analogue of lentigo maligna on mild / moderately sun damaged skin (J Cutan Pathol 2007;34:296)
- May recur locally
- Distinct from acral lentiginous melanoma, lentigo maligna and superficial spreading melanoma
Epidemiology
- Middle aged and elderly (Arch Pathol Lab Med 2011;135:337)
- Slight female preponderance
Sites
- Trunk, head / neck and proximal upper extremity (Arch Pathol Lab Med 2011;135:337)
Microscopic (histologic) description
- Broad lentiginous proliferation of melanocytes at dermoepidermal junction, both as single cells and as small nests with areas of confluent growth, extending to edges of biopsy
- Prominent atypia of melanocytes and invasion may be evident only at excision
- Preservation of retiform epidermis
- Similar to other histologic subtypes with a lentiginous junctional proliferation (lentigo maligna, acral lentiginous and mucosal lentiginous)
- Variable dermal fibrosis
- No solar elastosis
Differential diagnosis
