Skin-melanocytic tumor
Nevi
Lentiginous nevus

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

Revised: 22 February 2017, last major update February 2017

Copyright: (c) 2003-2017, PathologyOutlines.com, Inc.

PubMed Search: lentiginous nevus[title]
Cite this page: Lentiginous nevus. PathologyOutlines.com website. http://pathologyoutlines.com/topic/skintumormelanocyticlentiginousmelanocyticnevus.html. Accessed November 19th, 2017.
Definition / general
Terminology
Epidemiology
  • Speckled lentiginous nevus syndrome: hyperhidrosis, muscular weakness, dysesthesia or other neurological abnormalities
Clinical features
  • Often benign mole with increase in size, formation of irregular borders or peripheral change in color
  • May be due to "reactivation" of radial proliferation
  • Usually 5 mm or less
  • Note: atypia often present in childhood acral lesions (Pediatr Dev Pathol 1998;1:388)
Case reports
Treatment
  • Excision of speckles or entire lesion
Clinical images

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Macular hyperpigmentation and superimposed darker macules

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Speckled lentiginous nevus

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Adjacent type with a thick hypertrichotic inferolateral portion

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Admixed type hypertrichotic hybrid nevus

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Large unilateral speckled lentiginous nevus

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Extensive speckled lentiginous nevus

Microscopic (histologic) description
  • "Shoulder" area of lentiginous junctional melanocytic proliferation beyond lateral border of underlying dermal nevus
  • Elongation of rete ridges with small nests of melanocytes at tips of rete
  • Individual unit melanocytes extending along sides of rete, often mild lymphohistiocytic infiltrate with pigment incontinence
  • No atypia, no pagetoid spread and no dermal fibrosis
  • Acral lesions: resemble dysplastic nevus due to elongation of rete ridges, continuous proliferation of melanocytes at dermoepidermal junction, single scattered melanocytes or less commonly small clusters within the upper epidermis; poor or absent lateral circumscription, melanocytes with abundant pale cytoplasm and round / oval, sometimes hyperchromatic nuclei and prominent nucleoli present at the dermoepidermal junction; however, unlike dysplastic nevi, they lack anastomosing rete ridges, cytological atypia and well-formed lamellar fibroplasia (Histopathology 1995;27:549)

  • Variants:
    • Macular variant: "jentigo" pattern (lentiginous pattern plus nests of melanocytes at dermal-epidermal junction) in the darker speckles and by some nests of melanocytes at the dermoepidermal junction at the tips of the papillae, but background pigmentation has microscopic features of lentigo; tan-brown background with dark flat speckles in relatively even distribution resembling polka dots; associated with phacomatosis pigmentovascularis
    • Papular variant: dermal or compound melanocytic nevi; light-brown macule superimposed by multiple melanocytic nevi in the form of papules or nodules that show a more uneven distribution reminiscent of a star map; small dark macules may be present; associated with phacomatosis pigmentokeratotica or speckled lentiginous nevi syndrome (Dermatology 2006;212:53)
Microscopic (histologic) images

Images hosted on other servers:
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Nests of small and monomorphic melanocytes at the
dermoepidermal junction and within the reticular
dermis, with many melanocytes concentrated around
blood vessels and adnexal structures

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Elongated rete ridges and lentiginous proliferation
of melanocytes at the dermal-epidermal junction

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Prominent basal layer pigmentation similar to that
seen in lentigo simplex

Differential diagnosis