Vulva
Malignant neoplasms
Pigmented lesions

Author: Priya Nagarajan, M.D., Ph.D. (see Authors page)

Revised: 9 October 2017, last major update April 2015

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Pigmented vulvar lesions

Cite this page: Nagarajan, P. Pigmented lesions. PathologyOutlines.com website. http://pathologyoutlines.com/topic/vulvapigmented.html. Accessed November 19th, 2017.
Definition / general
  • This topic covers common nonmelamoma pigmented lesions of vulva
Epidemiology
Diagnosis
Case reports
Clinical images

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Hyperpigmented brownish macules

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Angiokeratoma of Fordyce

Microscopic (histologic) images

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Dowling-Degos disease

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Angiokeratoma of Fordyce



Images contributed by Dr. Priya Nagarajan:
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Normal

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Dysplastic nevus with mild atypia


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Dysplastic nevus with moderate atypia


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Dysplastic nevus with severe atypia

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Mucosal melanotic macule

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Mucosal melanotic macule, melanocytic cocktail (HMB45, MART1, tyrosinase)

Differential diagnosis
  • Acanthosis nigricans (Indian J Dermatol 2011;56:678, Fertil Steril 1993;59:583)
    • Clinical presentation:
      • Pigmented / brown velvety plaques
    • Histologic features:
      • Mild epidermal acanthosis, papillomatosis (usually with elongated, delicate papillae), hyperkeratosis, horn pseudocysts
      • Mild increase in basal layer pigmentation

  • Angiokeratoma (Eur J Gynaecol Oncol 2011;32:597, Acta Dermatovenerol Croat 2010;18:271)
    • Clinical presentation:
      • Dark papules and nodules
    • Histologic features:
      • Epidermal hyperkeratosis, acanthosis (often irregular) and low papillomatosis in close proximity to thin walled dilated blood vessels filled with red blood cells in papillary dermis

  • Dowling-Degos disease (Ann Dermatol 2011;23:205)
    • Clinical presentation:
      • Multiple symmetric pigmented papules
    • Histologic features:
      • Elongation and prominent pigmentation of epidermal rete ridges
      • No increase in melanocyte density
      • Suprapapillary plate thinning, pigment incontinence and hyperkeratosis may be present

  • Genital dysplastic nevi
    • Clinical presentation:
      • Irregular pigmented lesion, often on labia majora
    • Histologic features:
      • Features overlap with atypical genital nevi (J Cutan Pathol 2008;35:24, Am J Surg Pathol 2008;32:51)
      • More lentiginous spread and elongation of rete ridges may be seen
      • Lamellar eosinophilic fibroplasia of papillary dermis is present
      • Variable amounts of lymphohistiocytic inflammatory infiltrate may be present

  • Genital melanocytic nevi (Eur J Gynaecol Oncol 2002;23:323, J Cutan Pathol 2008;35:889, Dermatology 2010;221:55, Dermatol Online J 2010;16:9)
    • May affect about 2% of women
    • Any type of nevus can be seen in the vulva
    • Clinical presentation:
      • Irregular pigmented lesion up to 1 cm in size
      • Lesions typically involve labia minora, labia majora or mucosal aspect of clitoris
    • Histologic features:
      • Some degree of architectural disorder is allowed in special sites such as vulva
      • Nevi may be junctional or compound and may be asymmetrical
      • Junctional component is composed frequently of lentiginous proliferation of melanocytes, which is often nested
      • Nests may be large with retraction artifact and usually arise from the sides of rete ridges and may involve the suprapapillary plate
      • Adnexal extension may be seen
      • Dermal melanocytes mature with dermal descent
      • Overlying epidermis may be hyperplastic
      • Due to frequent irritation, features of trauma such as focal pagetoid spread of melanocytes, pigmented parakeratosis and transepidermal elimination of melanocytic nests may be seen

  • Genital melanosis (J Reprod Med 1993;38:5, Am J Dermatopathol 1985;7:51)
    • Clinical presentation:
      • Variably extensive and slowly developing pigmentation
    • Histologic features:
      • Hyperpigmentation of basal keratinocytes
      • Melanocyte density is usually normal or very mildly increased
      • Pigment incontinence in superficial dermis may be present

  • Lichen simplex chronicus (Dermatol Clin 2010;28:669)
    • Clinical presentation:
      • Dark, pigmented, thickened skin
    • Histologic features:
      • Epidermal acanthosis (may be slightly irregular), hyperkeratosis (often with presence of stratum lucidum), hypergranulosis
      • Fibrosis or presence of thickened, vertically oriented collagen fibers in papillary dermis
      • Superficial perivascular lymphohistiocytic infiltrate
      • Pigment incontinence may be present

  • Mucosal melanotic macules (J Am Acad Dermatol 2000;42:640, J Am Acad Dermatol 2014;70:e81)
    • Clinical presentation:
      • Dark asymmetrical macules
    • Histologic features:
      • Hyperpigmentation of basal keratinocytes
      • Melanocyte density is usually normal or very mildly increased
      • No nested or confluent proliferation of melanocytes

  • Normal vulvar pigmentation
    • When compared to the rest of the body, genital skin is usually more pigmented
    • Histologically, it is common to see at least some amount of melanin pigmentation within the basal keratinocytes
    • Therefore, it is important to know the baseline pigmentation of the patient, since the presence of basal keratinocytic pigmentation can be misleading, especially in small biopsies

  • Pigmented basal cell carcinoma (Dermatol Online J 2011;17:8, Acta Dermatovenerol Alp Pannonica Adriat 2011;20:81)

  • Pigmented condyloma acuminatum (J Dermatol 2014;41:337, J Dermatol 2012;39:860)
    • Clinical presentation:
      • Dark warty growths with fleshy or filiform appearance
      • Often multiple
    • Histologic features:
      • Epidermal acanthosis with hyperkeratosis and at least focal parakeratosis, with an undulating surface
      • Deep aspect of the lesion is fairly regular and sharply demarcated
      • Superficial keratinocytes with perinuclear halo, hyperchromatic nuclei and irregular / wrinkled nuclear contours (koilocytes), consistent with human papilloma viral cytopathic effect

  • Pigmented seborrheic keratosis (Clin Exp Dermatol 2005;30:17)
    • Clinical presentation:
      • Often multiple
      • Dark, brown papules or nodules with a stuck on appearance
    • Histologic features:
      • Epidermal acanthosis, low papillomatosis, hyperkeratosis and horn pseudocysts

  • Pigmented vulvar intraepithelial neoplasia / pigmented bowenoid papulosis (Gynecol Oncol 1980;10:201, An Bras Dermatol 2014;89:825, J Am Acad Dermatol 2010;62:597)
    • Clinical presentation:
      • Dark plaques, papules
    • Histologic features:
      • Usual type vulvar intraepithelial neoplasia (squamous cell carcinoma in situ or Bowen disease) with full thickness keratinocytic atypia
      • Melanin pigment often in small dense clusters within the epithelium
      • Pigment incontinence may be present
      • Lichenoid lymphohistiocytic inflammatory infiltrate may be present

  • Postinflammatory pigmentary alteration (Dermatol Ther 2010;23:449)
    • Clinical presentation:
      • Slowly increasing pigmentation which is often the result of an inflammatory condition
      • Initiating inflammatory disease is frequently asymptomatic
    • Histologic features:
      • Prominent pigment incontinence with melanin lying free in the superficial dermis or more frequently, increased numbers of pigmented melanophages
Additional references