Vulvar Melanoma: Review of Diagnosis, Staging, and Therapy

Management of Noncutaneous Melanomas

Noncutaneous melanomas are rare subtypes of melanoma with high rates of metastatic disease and poor overall survival. One-third to one-half of cases are amelanotic, which may contribute to a delay in diagnosis. Immunohistochemistry staining with typical melanoma markers helps confirm the diagnosis. There is no standard staging system across mucosal melanomas. Elective nodal dissection is not recommended and there is a paucity of data to support use of sentinel lymph node biopsy. Mutational analysis should be routinely performed. Systemic therapy options include targeted inhibitors, immunotherapy, and cytotoxic chemotherapy, although further studies are needed to confirm their efficacy.

Vulvar malignant melanoma: Pathogenesis, clinical behaviour and management: Review of the literature

Vulvar malignant melanoma (VMM) is a rare disease, accounting for 5% of all vulvar malignancies and is characterized by low survival and high recurrence rates. It is considered as a distinct entity of mucosal melanoma. Prognostic factors are higher age, advanced Breslow thickness, and lymph node involvement whilst central localization and ulceration status are still under debate. Surgery is the cornerstone for the treatment of primary VMM, however, it can be mutilating due to the anatomical location of the disease. Elective lymph node dissection is not part of standard care. The value of sentinel lymph node biopsy in VMM is still being studied. Radiation therapy and chemotherapy as adjuvant treatment do not benefit survival. Immunotherapy in cutaneous melanoma has shown promising results but clinical studies in VMM are scarce. In metastatic VMM, checkpoint inhibitors and in case of BRAF or KIT mutated metastatic VMM targeted therapy have shown clinical efficacy. In this review, we present an overview of clinical aspects, clinicopathological characteristics and its prognostic value and the latest view on (adjuvant) therapy and follow-up.

Prognostic factors and treatment outcomes in 444 patients with mucosal melanoma

BACKGROUND

Mucosal melanoma (MM) is a rare but diverse cancer entity. Prognostic factors are not well established for Caucasians with MM.

PATIENTS AND METHODS

We analysed the disease course of 444 patients from 15 German skin cancer centres. Disease progression was determined with the cumulative incidence function. Survival times were estimated with the Kaplan-Meier method. Prognostic parameters were identified with multivariate Cox regression analysis.

RESULTS

Common anatomic sites of primary tumours were head and neck (MMHN, 37.2%), female genital tract (MMFG, 30.4%) and anorectal region (MMAN, 21.8%). MMAN patients showed the highest vertical tumour thickness (p = 0.001), had a more advanced nodal status (p = 0.014) and a higher percentage of metastatic disease (p = 0.001) at diagnosis. Mutations of NRAS (13.8%), KIT (8.6%) and BRAF (6.4%) were evenly distributed across all tumour site groups. Local relapses were observed in 32.4% and most commonly occurred in the MMHN group (p = 0.016). Male gender (p = 0.047), advanced tumour stage (p = 0.001), nodal disease (p = 0.001) and incomplete resection status (p = 0.001) were independent risk factors for disease progression. Overall survival (OS) was highest in the MMFG group (p = 0.030) and in patients without ulceration (p = 0.004). Multivariate risk factors for OS were M stage at diagnosis (p = 0.002) and incomplete resection of the primary tumour (p = 0.001).

CONCLUSION

In this large series of MM patients in a European population, anorectal MM was associated with the poorest prognosis.

Malignant Melanoma of Vulva and Vagina: A Histomorphological Review and Mutation Analysis--A Single-Center Study

OBJECTIVES

The aim of this work was to determine molecular characteristics and specifically, the frequency of BRAF, C-KIT, and NRAS mutations in vulvar and vaginal melanomas.

METHODS

A retrospective review of all cases of vulvar and vaginal melanoma between 2002 and 2013 was performed. We reviewed the clinical and histological characteristics of all cases and performed genotyping studies on cases that had tissue available for the study, using next-generation sequencing.

RESULTS

We identified 33 vulvar and 11 vaginal melanomas in women with mean ages 58 and 61 years, respectively. Next-generation sequencing analysis on 20 cases (15 vulvar and 5 vaginal) identified a BRAF mutation in 7.6%, C-KIT mutation in 27.6%, NRAS mutation in 27.6%, and TP53 mutation in 7.6% of the vulvar cases. We detected only a single TP53 mutation in the vaginal cases. We did not identify any statistically significant relationship between the mutation status and patients' outcome, depth of invasion, ulceration, stage at presentation, or lymph node metastasis.

CONCLUSIONS

BRAF mutations are infrequent, whereas C-KIT and NRAS mutations are seen with higher frequency in vulvar melanomas than melanomas of other sites. These mutations can be considered as potential therapeutic targets in patients harboring them. Further studies are necessary to increase our understanding of mutational events occurring in melanoma of the lower female genital tract and their relationship with clinical parameters/outcome.

Malignant melanoma of the urethra: a rare histologic subdivision of vulvar cancer with a poor prognosis

Malignant melanoma of the urethra is a rare tumour that is difficult to diagnose and treat, resulting in a poor prognosis. In this paper, we present the case of a 65-year-old woman who was referred to a gynaecologist because of a urethral mass that mimicked a caruncle. The tumour was removed by local excision, and a pathological analysis revealed a malignant melanoma. Distal urethrectomy was performed after three months with no evidence of residual tumour. There was no evidence of disease at a six-year followup. In this paper, we compare the epidemiology, treatment, staging, and prognosis of vulvar cancer in general to malignant melanoma of the vulva in particular.

Melanoma of the vulva: a pigmented lesion is also significant in a non-sun-exposed area

PURPOSE

The foremost important aetiological factor for malignant melanoma is considered to be sunlight exposure. However, primary lesions are also seen in non-sun-exposed areas. Vulvar melanoma is rare and associated with impaired outcome. Herein, we attempt to increase physicians' awareness for early diagnosis in order to improve prognosis.

CASE REPORT

A 64-year-old female presented with pruritus and irritation at her external genitalia. At examination a pigmented lesion of the vulva 3 cm in diameter was seen. Incisional biopsy revealed melanoma. Clinical examination and imaging studies did not show evidence for metastatic disease. She underwent wide excision of the melanoma with primary wound closure and biopsy of sentinel lymph nodes, which were free of disease. After a follow-up period of 43 months, she remains free of disease.

CONCLUSIONS

Literature review shows that prognosis is poorer than at other sites, most probably due more advanced disease at diagnosis. This case demonstrates that early diagnosis by physicians aware of this malignancy at this relatively rare site is of crucial importance since it may result in improved outcome, similar to that of melanoma at more common sites.

Old and new perspectives in the management of high-risk, locally advanced or recurrent, and metastatic vulvar cancer

During the last decades there has been a continuing evolution in the surgical approach of squamous cell carcinoma of the vulva that has been traditionally treated with radical vulvectomy and bilateral inguinal-femoral lymphadenectomy. Patients with T1 tumour are usually treated with radical local excision, if the lesion is unifocal and the remainder of the vulva is normal. Patients with T1a disease have no risk of groin metastases and do not need lymphadenectomy, whereas those with T1b disease need ipsilateral inguinal-femoral lymphadenectomy if the lesion is lateral, and bilateral lymphadenectomy if the lesion is midline. Modifications of the surgical technique of deep femoral lymphadenectomy and the mapping of sentinel node can offer new interesting therapeutic perspectives. Postoperative adjuvant pelvic and groin irradiation is warranted for patients with two or more or macroscopically involved groin nodes. Locally advanced squamous cell carcinoma of the vulva has been long surgically treated with en-block radical vulvectomy and bilateral inguinal-femoral lymphadenectomy plus partial resection of urethra, vagina or anum, or by exenteration, with severe postsurgical complications, poor quality of life, and unsatisfactory survival rates. 5-Fluorouracil [5-FU] or 5-FU- and cisplatin-based chemotherapy concurrent with irradiation followed by tailored surgery represents an attractive therapeutic option for advanced disease, planned to avoid such ultra-radical surgical procedures and, hopefully, to improve patient outcome. Chemotherapy has also been used in neoadjuvant setting, with contrasting and generally unsatisfactory results, and in palliative treatment of patients with distant metastases. Surgery is the primary treatment also for vulvar malignancies other than squamous cell carcinoma, whereas the clinical usefulness of adjuvant irradiation or chemotherapy is still to be defined. Primary chemoradiation can be also used for advanced carcinoma of the Bartholin gland or for advanced adenocarcinoma associated with extramammary Paget's disease. The drugs used for chemotherapy of metastatic melanomas or sarcomas of the vulva are the same employed for the melanomas or sarcomas developed in other sites.