Benign vulvar melanosis (melanotic macule or genital lentigo) consists of a brown discoloration and is generally asymptomatic (Fig. 2). Table 2 outlines the symptoms, clinical appearance, differential diagnosis, and therapy of melanosis. It can be found in a variety of vulvar locations including the periurethral area (22). Often, there will be more than one lesion present. Melanosis may be found incidentally during a pelvic examination. Melanosis of the vulva may mimic melanoma on visual appearance with intensely pigmented irregular macules (Fig. 3) (23-25).

The size of the various forms of melanosis varies, but it tends to be several millimeters (general range of 1-15 mm in diameter) (26). The margins vary from smooth to jagged. There is an even distribution of brown to black pigmentation. This condition is not associated with systemic diseases or induced by sunlight exposure. It may occur in episiotomy sites. At times, lentigines may be an expression of a genetic disorder such as Peutz-Jeghers syndrome or LEOPARD syndrome. Also, they have been reported in association with lichen sclerosus (27). The patient in Figures 4 and 5 has extensive lentigos, and, in addition, a biopsy from her superior right vulvar aspect revealed thick hyperkeratosis with changes in the papillary dermis of lichen sclerosus.

If small, and the area is concerning, an excisional biopsy is recommended to completely remove the area of concern for diagnostic confirmation. If the darkened area is large, an incisional biopsy may be performed.

Table 2 Melanosis

Diagnosis Symptoms

Clinical appearance

Differential diagnosis


Melanosis Asymptomatic Pigmentation;

Melanoma Atypical junctional melanocytic hyperplasia Vulvar intra-

Generally, no therapy irregular tan to brown/black patches required once diagnosis is established

Margins can be jagged or smooth epithelial neoplasia

Seborrheic keratosis

Vulva Inspection
Figure 3 Diffuse darkening, grossly suspicious for melanoma; however, a biopsy revealed melanosis (lentigo).


On visual inspection of the vulva, it can be difficult to differentiate melanosis from melanoma; however, it is not difficult on histologic grounds. Melanosis lacks a substantial melanocytic proliferation, nesting pattern of melanocytes, or melanocyte atypia. Dendritic melanocytes are normal in number or only slightly increased along the basal layer of the epidermis in association with hyperpigmentation (Fig. 6). On occasion, the melanin pigment is also located in the upper dermis. Acanthosis may be present (28).

Vulva Inspection
Figure 4 Lentigo extensively involving the vulva. Of note, pruritus present on superior right vulva. This patient was found to have lichen sclerosus as well as the itch-scratch cycle.
Melanosis Labia Minora
Figure 5 Higher magnification of extensive lentigo involving both labia minora.


Melanosis is a benign process, and thus no treatment is needed once the diagnosis is made (24). However, it is important to visualize the entire vulva when examining these patients and consider biopsy if any areas are concerning. Figure 7 demonstrates VIN 3 with a darkened, gray-brown appearance. At times, VIN may be associated with melanosis (Fig. 8).

Vulva Insert
Figure 6 (See color insert) Melanotic macule (lentigo and melanosis). Basal layer hyperpigmentation is seen without an increase in melanocytes or melanocytic atypia.
Interlabial Sulci
Figure 7 Gray-brown vulvar intraepithelial neoplasia on the right interlabial sulcus.

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  • Matthias
    Can vulvar VIN be brown pigmentation?
    7 years ago
    What is vular melanosis desiese?
    7 years ago
  • yusef
    What is vulvar melanosis?
    6 years ago
  • edward minor
    Is vulvar melanosis common in the periurethral area?
    6 years ago
    Is it necessary to biiopsy vulva for melanosis?
    5 years ago
  • matthias
    How big can a left labia minor benign melanotic macule grow?
    5 years ago
  • Murrin Hamilton
    Can vulvar melanosis become malignant?
    4 years ago
  • medardo
    What is vulvar melanosos?
    4 years ago
  • tuomas saisio
    How to reduce vulvar melanosis?
    4 years ago
  • Leo
    Is vulva melantic macule dangerous?
    4 years ago
  • mollie
    Can you get lentigines on labia?
    4 years ago
  • leevi suorsa
    Does benign vaginal melanosis turn into melonoma?
    4 years ago
  • clorinda
    Is vulvar melanosis dangerous?
    3 years ago
  • grant
    Can you get melanosis on your labia?
    3 years ago
  • eden yohannes
    What is the medical implications of big labia majora?
    3 years ago
  • fiorenza
    Are genital lentigines dangerous?
    3 years ago
  • Ilse
    What causes darkening of labia minora?
    2 years ago
  • matti
    What causes black skin on labia?
    2 years ago
  • ollie
    What causes labia minora to grow?
    1 year ago
  • andreas
    Where is the vulva found?
    1 year ago
  • semolina
    What is the reason of big labia minora?
    11 months ago
  • Kaiden Watt
    How does a black vulva look like?
    11 months ago
  • amaranth gaukrogers
    What happens when labia minora grows?
    10 months ago
  • karin
    Is blackish discolouration common near vaginal area?
    7 months ago

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