Melanoma is a malignant tumor of melanocytes, which are the cells that make the pigment melanin and are derived from the neural crest. Although most melanomas arise in the skin, they may also arise from mucosal surfaces or at other sites to which neural crest cells migrate, including the uveal tract. Uveal melanomas differ significantly from cutaneous melanoma in incidence, prognostic factors, molecular characteristics, and treatment. (Refer to the PDQ summary on Intraocular (Uveal) Melanoma Treatment...
Carcinomas of the vagina are uncommon tumors comprising about 1% of the cancers that arise in the female genital system.[1,2]
Early stage tumors are often curable with local modality therapies, but there is no standard treatment of proven efficacy for metastatic disease. A large proportion (30%-50%) of women with vaginal carcinomas have had a prior hysterectomy for benign, pre-malignant, or malignant disease.[2,3]
The American Joint Committee on Cancer (AJCC) staging system indicates that tumors in the vagina that involve the cervix of women with an intact uterus are classified as cervical cancers. Therefore, tumors that may have actually originated in the apical vagina but extend to the cervix would be classified as cervical cancers.
Squamous cell cancer (SCC) accounts for approximately 85% of vaginal cancer cases. SCC initially spreads superficially within the vaginal wall and later invades the paravaginal tissues and the parametria. Distant hematogenous metastases occur most commonly in the lungs, and less frequently in liver, bone, or other sites. SCC of the vagina is associated with a high rate of infection with oncogenic strains of human papillomavirus (HPV) and has many risk factors in common with SCC of the cervix.[6,7,8] HPV infection has also been described in a case of vaginal adenocarcinoma.
Approximately 5% to 10% of cases of vaginal cancers are adenocarcinomas. A rare form of adenocarcinoma (clear cell carcinoma, described below) occurs in association with in utero exposure to diethylstilbestrol (DES), with a peak incidence at young ages (less than 30 years). However, adenocarcinomas that are not associated with DES exposure occur primarily during postmenopausal years.
The association between the clear cell carcinomas and in utero exposure to DES was first reported in 1971. The incidence of this disease, which is highest for those exposed during the first trimester, peaked in the mid-1970s, reflecting the use of DES in the 1950s. It is extremely rare now. However, women with a known history of in utero DES exposure should be carefully followed for this tumor.