A 91-year-old female was referred by the Gynaecologist for a 5cm polypoidal urethral lump and gross haematuria. She had no other urinary symptoms. Preliminary IVU and urine cytology were normal. Cystoscopy showed normal bladder mucosa. A localised excision biopsy of the lesion was performed.

The histology report confirmed a malignant melanoma of the urethra (Fig 3). No other primary was found. She remained continent following surgery. Owing to frail health she was not considered suitable for radical surgery, radiotherapy or chemotherapy.

Six months after excision she was found to have a black spot on the right labium minora, suggestive of metastasis (Fig 1). However the inguinal lymph nodes were not palpable.

A repeat flexible cystoscopy at twelve months showed a recurrent melanoma at the urethra (Fig 2). Although the bladder mucosa was normal, there was an increase in the size of the labial recurrence.

Figure 1

Figure 1: Recurrent malignant melanoma on the medial aspect of Rt. Labial Minora.

Figure 2

Figure 2: Local recurrence seen at the urethra. Indwelling catheter seen.

Figure 3

Figure 3: High power photomicrograph of the tumour showing pleomorphic epitheliod cells with abundant melanin pigment. (Haematoxylin and Eosin x400)

Discussion

Primary malignant melanoma of the female genitourinary tract is rare and a disease of the old age group with an average age of 64 years(range 32-90). The disease is three times more common in women than men.₁

The tumour is usually pigmented, varying in colour from black to blue or brown. It may easily be confused with a caruncle. The tumour usually arises in the distal portion of the urethra. It may spread via the superficial lymphatics to the vulva and vagina, by the deep lymphatics to the inguinal lymph nodes and haematogenously throughout the body.

Delay in diagnosis is a major factor influencing the course of the disease, thus increasing the likelihood of regional node involvement and distant metastasis. This is often due to the patient's reluctance to seek advice, or difficulty in recognising the disease by the physician.

Despite major surgery, radiotherapy or immunotherapy; malignant melanoma usually has a poor prognosis.₂ Most patients do not survive more than three years. However, an untreated case of malignant melanoma with liver metastasis surviving a 5-year period has been reported.₃ Therefore, in women presenting with urethral lesions a diagnosis of malignant melanoma should be considered and an urgent urological opinion sought.