Mucosal Melanoma (Genital)
Elsa F. Velazquez, MD
Key Facts
Clinical Issues
Vulva (most frequent site in females)
Glans penis (most common site in males)
Flat to nodular to polypoid lesions
Amelanotic, brown to black
Foci of regression appear red, gray, or white
Microscopic Pathology
Different histological variants may affect genital area
Lentiginous
Superficial spreading
Nodular
Desmoplastic/neurotropic
Top Differential Diagnoses
Atypical genital nevi
Nevi associated with lichen sclerosus
SCC (in situ and invasive)
Paget disease
 Clinical photograph shows a mucosal melanoma on the glans penis of an elderly patient. Histologic examination showed an invasive nodular type melanoma. |
 Mucosal melanoma in situ of the vulva shows a lentiginous and confluent pattern of growth without significant pagetoid spread (similar to lentigo maligna)  . |
TERMINOLOGY
Abbreviations
Mucosal malignant melanoma (MMM)
Synonyms
Vulvar melanoma, vaginal melanoma, penile melanoma, scrotal melanoma
Definitions
Malignant tumor of melanocytes
ETIOLOGY/PATHOGENESIS
Unknown in Most Cases
Alterations in KIT (~ 30% of cases)
NRAS mutations have been reported
6% are associated with nevi
Family history and genetic susceptibility
CLINICAL ISSUES
Epidemiology
Incidence
Rare
˜ 2% of all melanomas in females
Even less frequent in males
Age
6th to 7th decade
Site
