Vulvar melanoma

Definition

Vulvar Melanoma

• Incidence: Vulvar melanoma is the second most common malignant tumour of the vulva.
• Clinical presentation: Suspicious findings are newly appeared, irregularly pigmented, asymmetrical lesions with an indistinct border, bleeding, or an increase in size.
• Location: The most common locations are the clitoral region and the labia minora, i.e., non-hair-bearing parts.
• Prognostic factor: The decisive prognostic factor is the tumour thickness according to Breslow.

• Vulvar melanoma is a malignant melanocytic tumour of the vulva; the vulva is the most common site of melanoma in the female genital tract.

Classification

• The mucosal lentiginous subtype is the most common histologically; nodular and superficial spreading melanomas are also described.

Occurrence & epidemiology

Epidemiology

• It is the second most common malignant tumour of the vulva after squamous cell carcinoma.
• Mainly white women from the fifth to the seventh or eighth decade are affected; the mean age at diagnosis is 60–63 years.

Aetiopathogenesis

Aetiology and risk factors

• The relationship with sun exposure is undefined.
• KIT mutations are molecularly characteristic; BRAF and NRAS mutations also occur.

Clinical features

• Tumours occur, in descending order of frequency, on the labia majora, labia minora and clitoral hood, mainly on hairless mucosa; only about 13 % affect the outer hair-bearing skin.
• Symptoms are non-specific: itching, bleeding or atypical discharge and a sensation of a lump, with lymphadenopathy in advanced disease; some tumours are asymptomatic.
• Amelanotic forms account for 2–10 % and are more common after the menopause; clinical presentation is often delayed because early symptoms are absent.

Diagnosis

• The diagnosis is made by biopsy and confirmed by immunohistochemistry, for amelanotic lesions for example with HMB-45, S-100, MART-1 and tyrosinase.
• Micro-staging follows Clark, Breslow and Chung; dermoscopy and confocal microscopy support the clinical assessment.

Keep learning in the app

Further reading (selection)

1. Vulvar Malignant Melanoma: A Narrative Review (Cancers 2022, PubMed Central)
2. DocCheck Flexikon, Morbus Paget

Cross-references