Background: Primary malignant melanoma of the urethra is a rare tumour that most commonly affects the meatus and distal urethra. General prognosis seems to be poor. To date, there have been no systematic reviews on this topic. Therefore, we aimed to gain more insight into this rare type of tumour.
Methods: Medline and PubMed were searched and all cases of urethral melanoma reported as single case reports or small case series were reviewed as the first step in the combined analyses of all the cases reported.
Results: We reviewed 150 cases. The most frequent presentation was urethral mass. The first line of treatment was surgery such as tumour excision or total urethrectomy. Three times more women were diagnosed than men with a mean age of 64.7 years (SD 10.7; median 65.5; range 28-96 years). Forty-three patients (36 %) underwent adjuvant treatment including chemotherapy, radiotherapy or immunotherapy. Recurrences were observed in 71.4 % (n = 80) of the cases, mainly local recurrences (n = 44; 55 %) and metastases in the inguinal lymph nodes (n = 31; 28 %). Recurrences occurred within 12.5 months on average (SD 12.6; range 1-48). The treatments of recurrences were surgery, chemotherapy, radiotherapy and immunotherapy. These treatment options influenced the course of the disease.
Conclusions: Urethral melanoma is mainly a disease of older people with an average age of 64 years. The study showed that the T-stage as a basis of depth invasion is a prognostic factor for urethral melanoma. Moreover, pulmonary metastases (cM2), local recurrence and systemic recurrence influence prognosis. The T-stage classification is useful because of its prognostic ability.