(Video Poster 28) An Unexpected Case of Primary Malignant Vaginal Melanoma Presenting as Prolapse

Objectives: To review a case of primary malignant melanoma presenting as pelvic organ prolapse. As well as discuss common and rare etiologies of vaginal bulge and associated epidemiology.

Methods: In this video, we review a case of a 33-year-old G0 who presented to Urogynecology Clinic as a self-referral following a coughing fit that precipitated new onset vaginal bulge. On initial exam a flesh-colored firm, friable pelvic mass was noted originating from the 1-3 O'Clock position along the anterior vaginal wall near the introits. The mass was approximately 4cm x 2cm x 3.5cm in size without evidence of pelvic organ prolapse. The patient was referred to Gynecologic Oncology and underwent biopsy with resulting finding of primary malignant vaginal melanoma. She subsequently underwent an excisional procedure followed by positron emission tomography revealing fluorine-18-deoxyglucose avidity along the left vaginal wall. She was ultimately referred to Medical Oncology for further treatment. Review of epidemiologic data for etiologies of vaginal bulge was conducted. The highest incidence was pelvic organ prolapse followed by multiple benign masses and then more rarely by vaginal malignancies.

Clinical Relevance: Vaginal melanoma can be amelanocytic and present as a flesh-colored vaginal bulge. Patients and or providers may interpret a mass such as this as pelvic organ prolapse and request Urogynecology evaluation, as in this case. Primary malignant vaginal melanoma makes up less than 0.2% of all melanomas and 3% of all vaginal cancers. Vaginal melanoma is more aggressive than cutaneous forms of melanoma with a 5-year survival rate less than 30% despite treatment. Patients with suspected vaginal melanoma require prompt Oncology referral to provide them with the best possible outcome.