Genitourinary melanoma: An overview for the clinician

Abstract

Genitourinary (GU) melanoma is a rare presentation of melanoma accounting for approximately 0.5% of all melanomas. GU melanomas include primary melanomas of the vulva, vagina, uterine cervix, ovary, penis, scrotum, urethra, bladder, ureter, and kidney. These melanomas are often diagnosed in advanced stages and stigma is thought to contribute to delays in presentation. As the likely diagnosing provider, it is imperative that dermatologists, urologists, and gynecologists are aware of these uncommon sites of presentation. While there have been major advances in the treatment of melanomas as a whole in the last 10 years, their applications to GU melanomas have often been overlooked. GU melanomas have not been included in many of the major phase III clinical trials which brought contemporary advanced treatments to market and the prognoses for GU melanomas remain poor. Due to the rarity of GU melanomas, much of the literature provides generalized recommendations across multiple different organs affected by GU melanomas or omits certain topics, making it difficult to appreciate the fundamentals of the individual presentations. This review aimed to provide background information on the pathogenesis and epidemiology of the different sites of GU melanomas and categorize data specific to the presentation, staging, treatment, and prognosis of each type of GU melanoma to guide the clinician. It was also meant to encourage a multidisciplinary approach to the management of these patients as it spans the expertise of surgical oncologists, medical oncologists, radiation oncologist, dermatologists, urologists, and gynecologists.

Keywords: Female; Genitalia; Male; Melanoma; Rare diseases; Staging; Treatment; Urinary tract.

Figure 1

Melanoma of the left labium minus with clinically and radiographically node-negative disease undergoing modified radical left vulvectomy with lymphoscintigraphy-guided sentinel lymph node biopsy. (A) Vulvar melanoma visible only after retraction of the labia majora; (B) Margins of resection; (C) Specimen for pathology; (D) Closure of modified radical left vulvectomy (images courtesy of Mitchel S. Hoffman, M.D. and Jonathan S. Zager, M.D.).

Figure 2

Melanoma of the glans penis with biopsy-proven right inguinal nodal involvement undergoing partial penectomy with ventral phalloplasty and right inguinal complete lymph node dissection. (A and B) Penile melanoma presentation after retraction of the foreskin; (C and D) margins of resection; (E) specimen for pathology; (F) closure of partial penectomy with ventral phalloplasty and right inguinal lymphadenectomy (images courtesy of Philippe E. Spiess, M.D. and Jonathan S. Zager, M.D.).