Malignant melanoma of the male urethra: a case report

Malignant melanoma of the penis is a rare malignancy, and accounts for less than 2% of all primary penile malignant lesions. Most cases occur in 6th and 7th decades of life. Most frequently, the lesion is located on the glans(55%), followed by foreskin(28%), penile shaft(9%) and urethral meatus(8%). 5-year survival is 31%.A 52-year-old man presented to hospital with history of a lesion extruded from urethral meatus. He did not mention any complaints of pain or lower urinary tract symptoms. On physical examination, there were no remarkable findings. No palpable inguinal lymphadenopathy was found.During cystoscopy, a grayish-brown mass was detected in the urethra. The lesion was resected and specimens were sent to pathology. IHC and histopathologic findings were in favor of malignant melanoma. Spiral chest and abdominopelvic CT-scan and whole body bone scan indicated no evidence of metastasis. The patient underwent partial penectomy and bilateral inguinal lymphadenectomy therewith. Subsequent pathology examination confirmed malignant melanoma with tumor size of 2.8cm in greatest diameter, and maximum tumor (Breslow) thickness of 8mm. Tumor was classified as stage2B according to AJCC TNM staging system(T4aN0M0).Ultra-Sound imaging of kidneys, ureters, bladder, penis and testes was performed and no remarkable findings were detected. The patient underwent total body PET-CT scan and abdominopelvic MRI with and without contrast; A hypodense hyper-metabolic lesion was indicated in favor of perineal abscess. Serology, biochemistry and hematologic investigations were all normal. After surgery, interferon-therapy was started for the patient as 5,000,000 units of alpha-interferon every other day for one year. Penile melanomas are usually diagnosed late; Many might have already invaded into deep anatomical structures and inguinal lymph-nodes at the time of diagnosis. Therefore, partial or total penectomy with inguinal lymph-node dissection is the treatment of choice. Early diagnosis and surgical treatment affect clinical prognosis.

کلیدواژه ها:

Melanoma ، Urethra ، Penis ، Penectomy