Skin melanocytic tumor

Blue nevi, dermal melanocytoses and associated neoplasms

Blue nevus / cellular blue nevus



Minor changes: 13 December 2021

Copyright: 2019-2022, PathologyOutlines.com, Inc.

PubMed Search: Blue nevus[TI] OR cellular blue nevus[TI] review[PT]

Ali M. Alani, M.D.
Carlos A. Torres-Cabala, M.D.
Page views in 2021: 17,473
Page views in 2022 to date: 1,399
Cite this page: Alani AM, Desar S, Torres-Cabala CA. Blue nevus / cellular blue nevus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticbluenevus.html. Accessed January 23rd, 2022.
Definition / general
Essential features
  • Blue nevi are not uncommon; more frequent in females (F:M = 2:1) and adults < 40 years
  • Common blue nevus is composed of bipolar spindle dendritic melanocytes associated with dense collagenous stroma
  • Cellular blue nevus is usually a biphasic lesion composed of fusiform to ovoid cells with clear cytoplasm, arranged in nests and surrounded by collagen, pigmented dendritic and bipolar cells and melanophages
  • Cellular and atypical cellular blue nevi lack high mitotic activity, atypical mitotic figures, necrosis and marked pleomorphism
Terminology
  • Dendritic blue nevus
  • Common blue nevus
  • Dermal dendritic melanocytic nevus
  • Nevus of Jadassohn
  • Tièche nevus
  • Jadassohn-Tièche blue nevus
ICD coding
  • ICD-O:
  • ICD-10:
    • D23.9 - other benign neoplasm of skin, unspecified
    • D22.9 - melanocytic nevi, unspecified
Epidemiology
Sites
Pathophysiology
Clinical features
  • Common blue nevus:
  • Cellular blue nevus:
  • Atypical cellular blue nevus:
    • Bluish deep dermal nodules
Diagnosis
  • Clinical presentation
  • Dermoscopy shows homogenous, structureless pigment pattern, with variety of colors (blue, white-blue, black, brown and polychromatic) (J Cutan Pathol 2007;34:543, J Am Acad Dermatol 2012;67:199)
  • Definite diagnosis is made on excision specimen through histologic examination
Case reports
Treatment
Clinical images

Contributed by Mark R. Wick, M.D.
Cellular blue nevus

Cellular blue nevus



Images hosted on other servers:
Missing Image

Giant cellular blue nevus

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Carlos A. Torres-Cabala, M.D.

Common blue nevus
Dendritic melanocytes and melanophages

Dendritic melanocytes and melanophages

Focal extension into subcutis

Focal extension into subcutis

Dense collagen stroma

Dense collagen stroma

Pigmented dendritic melanocytes

Pigmented dendritic melanocytes

Pigmented melanophages

Pigmented melanophages



Cellular blue nevus
Dermal spindle cells

Dermal spindle cells

Biphasic appearance

Biphasic appearance

Biphenotypic cytology

Biphenotypic cytology

Sharp demarcation between the 2 populations

Sharp demarcation between the 2 populations

Molecular / cytogenetics description
Sample pathology report
  • Common blue nevus:
    • Skin, hand, dorsum, right, punch biopsy:
      • Blue nevus, present at peripheral and deep tissue edges (see comment)
      • Comment: Histological sections reveal a proliferation of spindle shaped melanocytes admixed with abundant pigment laden macrophages in dense collagenous background. The spindle cells have bland cytologic features. These findings support the above diagnosis.
  • Cellular blue nevus:
    • Skin, buttock, right, ellipse:
      • Skin and subcutis with scar and cellular blue nevus, margins of resection are free of cellular blue nevus (see comment)
      • Comment: Sections show a dermal scar and an adjacent proliferation of spindle and epithelioid melanocytes occupying the dermis. Dendritic melanocytes showing classic blue nevus appearance are present at the periphery of the lesion. No nuclear atypia, necrosis or mitosis are identified. Immunohistochemical studies reveal the lesion cells to be diffusely positive for SOX10 and HMB45 and to show preserved expression of BAP1 (nuclear) and p16 (nuclear and cytoplasmic). The MIB1 proliferative rate is < 1%. These findings support the above diagnosis.
  • Atypical blue nevus:
    • Skin, forearm, right, ellipse:
      • Skin and subcutis with atypical blue nevus, present at peripheral margins of resection (see comment)
      • Comment: Sections show a proliferation of spindle and epithelioid melanocytes involving dermis and focally extending into subcutis. The melanocytes are arranged in nests and fascicles. The lower portion of the nevus shows infiltrative growth with mild cytologic atypia and minimal pleomorphism. Perineural invasion is present. Rare mitotic figures (1/mm²) are identified; however, abnormal mitosis or necrosis are not identified. Immunohistochemical studies were performed. The lesion cells are diffusely positive for HMB45. A double MART1 / Ki67 study reveals low proliferation rate. Preserved expression of BAP1 is noted, along with focal expression of p16. The lesion appears to be incompletely excised. Re-excision is recommended, if clinically indicated.
Differential diagnosis
Board review style question #1

A 28 year old woman presented with slow growing, 3 cm gray to dark blue solitary patch on her sacral skin. A biopsy specimen is shown. The best diagnosis is

  1. Cellular blue nevus
  2. Deep penetrating nevus
  3. Dermatofibroma
  4. Desmoplastic melanoma
  5. Mongolian blue spot
Board review style answer #1
A. Cellular blue nevus

Comment Here

Reference: Blue nevus / cellular blue nevus
Board review style question #2
Epithelioid blue nevus is associated with

  1. Carney complex
  2. Birt-Hogg-Dubé syndrome
  3. Muir-Torre syndrome
  4. Neurofibromatosis
  5. Tuberous sclerosis
Board review style answer #2
A. Carney complex

Comment Here

Reference: Blue nevus / cellular blue nevus
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