Vaginal melanoma

Vaginal melanoma is a rare malignancy that originates from melanocytes in the vaginal epithelium. It is also known as a melanocytic tumor or as a malignant melanoma.[1] It is aggressive and infrequently cured. The median overall survival is 16 months.[2] Vaginal melanoma accounts 5.5% of all vaginal cancers and only 1% of all melanomas diagnosed in women.[2] Vaginal melanomas are frequently diagnosed in advanced stages of the disease. The prognosis is poor and the most important risk factor is the presence of lymph node metastases.[2][3]

Vaginal melanoma
SpecialtyOncology/gynecology

Presentation

This cancer most often develops on the lowest third of the vagina. It is darkly pigmented and of an irregular T-shape, but amelanotic melanomas have been described in 7% of cases. Melanoma of the vagina can be several centimeters in size.[2][3]

Histology

When the tissue is assessed, the histological characteristics include:

  • the shape of the cells appear similar to epithelial and spindle-shaped
  • the growth occurs in the shapes of sheets and nests
  • the presence of melanin in the cells
  • the nucleus of the cells is large and abnormal

Other cancers

Other cancerous conditions arise from vaginal epithelium:[4]

Diagnosis

A biopsy should be obtained from all suspicious lesions and Immunocytochemistry can reveal positive results for S-110 protein, HMB 45 and melan A.[8] Once the diagnosis of vaginal melanoma is established, additional examinations should be performed to exclude the spread to regional lymph nodes or distant organs, as the diagnosis of vaginal melanoma is often delayed.[2] Lymph-node involvement is the most important prognostic factor.[2]

Treatment

Surgery represents the primary treatment modality. Chemotherapy may be ineffective, but checkpoint inhibitors and BRAF and MEK inhibitors have been recently tested in vaginal melanomas.[8] Less than 10% of vaginal melanomas have BRAF-mutations.[8][9] Therefore BRAF-inhibitors play only a minor role in vaginal melanomas (unlike in skin melanomas). However, a recent study has shown that checkpoint inhibitors (inkluding CTLA-4 inhibitors and PD-1 inhibitors) are effective in the treatment of advanced vulvovaginal melanomas.[9]

References
  1. "Vulva and Vagina tumors: an overview". atlasgeneticsoncology.org.
  2. Wohlmuth C, Wohlmuth-Wieser I, May T, Vicus D, Gien LT, Laframboise S (2019-11-29). "Malignant Melanoma of the Vulva and Vagina: A US Population-Based Study of 1863 Patients". American Journal of Clinical Dermatology. 21 (2): 285–295. doi:10.1007/s40257-019-00487-x. ISSN 1179-1888. PMC 7125071. PMID 31784896.
  3. Kalampokas E, Kalampokas T, Damaskos C (January 2017). "Primary Vaginal Melanoma, A Rare and Aggressive Entity. A Case Report and Review of the Literature". In Vivo. 31 (1): 133–139. doi:10.21873/invivo.11036. PMC 5354139. PMID 28064232.
  4. Chen L, Xiong Y, Wang H, Liang L, Shang H, Yan X (October 2014). "Malignant melanoma of the vagina: A case report and review of the literature". Oncology Letters. 8 (4): 1585–1588. doi:10.3892/ol.2014.2357. PMC 4156219. PMID 25202372.
  5. "Vaginal Cancer Treatment". National Cancer Institute. 1980-01-01. Retrieved 2018-02-08.
  6. "About DES". Centers for Disease Control and Prevention. Retrieved February 8, 2018.
  7. "Known Health Effects for DES Daughters". Centers for Disease Control and Prevention. Retrieved February 8, 2018.
  8. Wohlmuth C, Wohlmuth-Wieser I (December 2019). "Vulvar malignancies: an interdisciplinary perspective". J Dtsch Dermatol Ges. 17 (12): 1257–1276. doi:10.1111/ddg.13995. PMC 6972795. PMID 31829526.
  9. Wohlmuth, Christoph; Wohlmuth-Wieser, Iris; Laframboise, Stéphane (2020-11-24). "Clinical Characteristics and Treatment Response With Checkpoint Inhibitors in Malignant Melanoma of the Vulva and Vagina". Journal of Lower Genital Tract Disease. doi:10.1097/LGT.0000000000000583. ISSN 1526-0976. PMID 33252450.
Classification
External resources
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