Clinical Characteristics, Management and Prognosis of Patients with Vaginal Primary Malignant Melanoma

Androutsopoulos G*, Decavalas G

Department of Obstetrics and Gynecology, University of Patras, Medical School, Rion, Greece.

*Corresponding Author

Georgios Androutsopoulos MD,
Assistant Professor,
Department of Obstetrics & Gynecology,
University of Patras,
Medical School, Rion 26504, Greece.
Tel: +306974088092
E-mail: androutsopoulos@upatras.gr

Article Type: Editorial
Received: January 25, 2015; Published: February 02, 2015

Citation: Androutsopoulos G, Decavalas G (2015) Clinical Characteristics, Management and Prognosis of Patients with Vaginal Primary MalignantMelanoma. Int J Translation Community Dis. 3(1e), 1-3. doi: dx.doi.org/10.19070/2333-8385-150004e

Copyright: Androutsopoulos G© 2015. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.

Vaginal primary malignant melanoma (VPMM) is an extremely rare and highly aggressive tumor [1,2]. It accounts for less than 3% of all vaginal malignancies and 0.3-0.8% of all malignant melanomas [1-3]. It is the 2nd most common malignant melanoma of the female genital tract [4]. Until today, less than 300 cases of VPMM have been reported in the English literature [1,2,5,6].

The estimated annual incidence of VPMM is 0.026/100,000 women per year [2,3]. However between various racial or ethnic groups, there are no significant differences in VPMM annual incidence [3,7]. VPMM most commonly occurs in postmenopausal women [8-11]. The median age at diagnosis of VPMM, is 57 years[8-13].

Despite proposed theories, the precise pathogenesis of VPMM still remains unclear [14]. However, an attractive explanation is that VPMM arises from melanocytes located aberrantly in vaginal epithelium [14,15]. Those melanocytes are present in the basal layer of vaginal epithelium in 3% of healthy women [16]. According to this theory, active junctional changes is the initial stage in malignant melanoma development [17].

As VPMM located in areas not exposed to sunlight, it is obvious that ultraviolet radiation is not implicated in its pathogenesis [7].

Although VPMM may arise anywhere in the vagina, it most commonly occurs in the lower one third (34%) and the anterior (38%) vaginal wall [2,8,9,12,15,18,13]. VPMM lesions may be single or multiple, pigmented or nonpigmented [13,19]. Also, most of VPMMs are polypoid and ulcerated [14,19]. Moreover, the clinical appearance of nonpigmented VPMMs may be similar with vaginal epithelial tumors [14,19].

The most common symptoms and signs in patients with VPMM, are: vaginal bleeding (80%), vaginal discharge (25%), palpable vaginal mass (15%) and pain (10%) [5,6,8,9,11,12,14,20].

VPMM is a very aggressive tumor with a propensity of early spread and metastasis development [1,6,21,22]. The extensive vascular and lymphatic network of the vaginal mucosa, explains adequately the aggressive clinical behaviour of VPMM [8,10,20].

Most patients with VPMM, diagnosed with advanced stage disease [1,6,21,22]. More specifically, they have local recurrences in the pelvis and distant metastases in the lungs, liver, bones and brain [8,14]. However, many patients with distant metastasis have synchronous local recurrence in the pelvis [8].

The most common histologic cell type of VPMM, is: epithelioid (55%) [10,14,19]. Other less common histologic cell types of VPMM, are: spindled (17%) and mixed (28%) [10,14,19].

FIGO staging system for vaginal cancer does not incorporate tumor size and regional lymph node status and it is inappropriate for VPMM staging [2,12].

Although there are various treatment options, it has not defined yet an appropriate and effective treatment protocol for patients with VPMM [10,23].

Surgery is the baseline treatment in patients with VPMM [2,10,23,24]. The spectrum of surgical operation varies from conservative (wide local excision) to radical (vaginectomy, pelvic exenteration) [2,10,20]. In patients that wide local excision with clear margins is possible, the role of radical surgery remains unjustified [2,10,23,25]. However in highly selected patients that wide local excision is impossible, pelvic exenteration may be reasonable [2,13].

Lymph node dissection is not recommended in patients with VPMM, because the rate of lymph node metastasis is low [10]. Although lymph node dissection has no survival benefits for patients with VPMM, it leads to significant morbidity [10,23,26].

Moreover the role of elective lymph node sampling in patients with VPMM, remains controversial [2,10,23,24]. Recent years, sentinel lymph node biopsy has gained popularity [10,24,27].

Radiotherapy in patients with VPMM includes vaginal brachytherapy and external pelvic radiotherapy [2,10,28,29].

External pelvic radiotherapy is used as primary treatment for patients who are unable or unwilling to have surgery [2,10,28,29]. Also it is used as preoperative treatment, to reduce tumor size and enable a more conservative surgery [2,10,25,28,29]. Moreover it is used as postoperative adjuvant treatment for patients with tumor size ≥3 cm, incomplete tumor resection or pelvic metastases [2,10,11,23,28,29]. However, although external pelvic radiotherapy reduces the risk of local recurrences, it has no impact on overall survival [13,23,24].

Especially in elderly patients with bad performance status and relevant comorbidities, we prefer postoperative vaginal brachytherapy [5,11,30,31]. It is well tolerated and reduces the risk of local recurrences.[13] Moreover, it is associated with less side effects and better quality of life, compared with external pelvic radiotherapy [5,11,31].

The role of postoperative adjuvant chemotherapy in patients with advanced stage VPMM, remains controversial [32]. Postoperative adjuvant chemotherapy achieve only modest response rates and has no impact on overall survival [25].

Postoperative adjuvant immunotherapy with interferon (IFN) or interleukin-2 (IL-2), confers survival benefits in patients with VPMM at high risk for recurrence. [6,22,24,33-35]. Moreover, the combined use of IFN and IL-2 is superior to the single use of IL-2 [36]. However, the toxicity of immunotherapy is significant [6,22,33,34]. Moreover, IFN associated with the generation of autoantibodies and the induction of autoimmune disorders [37].

The role of combined use of chemotherapy and immunotherapy (biochemotherapy) in patients with advanced stage VPMM has not been established [38]. Moreover, the toxicity of biochemotherapy is significant [24,34].

Patients with VPMM have poor prognosis [35]. As most cases with VPMM diagnosed at advanced stage disease, the prognosis is very poor despite treatment modality [1,6,11,22].

Prognostic factors for patients with VPMM, are: tumor size, tumor growth, lymph node status and treatment method [8,12,23,35]. Among them, tumor size (<3 cm) is the most important prognostic factor [8,12,24]. Tumor thickness is only a weak predictor of survival, in patients with VPMM [8].

The 5-year overall survival of patients with VPMM is 8.4-32.3% [1,8,10,13,15,24,35]. Moreover the prognosis of VPMM is much more unfavourable, compared with other vaginal malignancies and cutaneous malignant melanoma [14].