Introduction
We present a rare case of primary vaginal malignant melanoma (pVMM) and discuss an evidence-based approach to investigate spread of disease.
Case Report
A 64-year-old female was referred to gynaecology outpatient clinic for investigation of a three-year history of post-menopausal bleeding. She has no significant past medical history. On examination, there was a 5cm lobular protruding irregular mass, with a broad base on the right side of the vagina. She underwent an examination under anaesthetic, hysteroscopy, cystoscopy, and biopsies. The vaginal mass measured 7 x 3 cm and was biopsied. Cystoscopy demonstrated no abnormalities. Hysteroscopy revealed a polypoidal appearing endometrium which was biopsied.
Vaginal histopathology confirmed pVMM, and endometrial biopsies showed focal endometrioid adenocarcinoma grade 1 with diffuse complex atypical hyperplasia. The patient was referred to Gynaecology Oncology, and subsequently underwent a pelvic exenteration with palliative immunotherapy.
pVMM is rare, accounting for less than 1% of all melanomas in females with an abysmal 5-year survival rate of 5-25% irrespective of treatment type. The pathogenesis of vaginal melanoma is poorly understood. Theories include the migration of melanocytes in vaginal mucosa and microenvironmental influence. Diagnosis involves physical examination and histopathological confirmation.
pVMM can have widespread effects and can involve the cervix, uterus, ovaries, vagina, bladder and parametrium. Upon confirmation of pVMM biopsy, based on the literature the following investigations are recommended (with biopsies as appropriate): 1) Speculum examination; 2) Examination under anaesthesia; 3) Cystourethroscopy; 4) Staging CT chest, abdomen and pelvis to assess metastatic involvement; 5) Consideration of MRI to distinguish melanoma from other tumours; and 6) Consideration of lymph node biopsy.
Conclusions
Vaginal melanoma is a rare and aggressive disease of the lower genital tract. It is important to consider a multisystem investigative approach upon a positive pVMM diagnosis due to the possibility of extensive involvement in disease progression.