Introduction/Purpose: Primary malignant melanoma to the urinary bladder accounts for 0.2% of all cases. To date, there are 28 reported cases of primary malignant melanoma of the bladder in the literature, making it an exceedingly rare lesion. We present the case of a 78-year-old female, with no prior history of melanoma, who presented with incontinence and gross hematuria. Subsequent workup led to cystectomy revealing histology and immunohistochemistry consistent with primary malignant melanoma. Extensive investigation with PET/CT did not reveal a melanotic tumor on metastatic work up.
Methods or Case Description: A 78-year-old female presented with incontinence and gross hematuria. CT urogram was performed and revealed a bladder mass along with left hydroureteronephrosis. Patient subsequently underwent transurethral resection of the bladder tumor with concurrent left ureteral stent placement. The tumor was unamenable to complete resection due to tumor size and location. She then underwent treatment consisting of radical cystectomy with ileal conduit, bilateral pelvic lymph node dissection, hysterectomy with bilateral salpingoopherectomy, and excision of anterior vaginal wall. Surgical margins as well as lymph nodes were all negative at the time of resection. Patient was unfortunately not a candidate for adjuvant therapy given her comorbidities.
Outcomes: The patient developed evidence of retroperitoneal, mesenteric metastasis, and pulmonary metastasis approximately 12 months after diagnosis. The patient subsequently succumbed to her metastatic disease sixteen months after her initial diagnosis.
Conclusion: Primary malignant melanoma of the bladder is exceedingly rare, yet poses great risk given its lethality with a mean survival time of 20 months. Due to the limited number of reported cases, it is essential to publish such cases as to better understand and characterize its behavior and histology in an effort to better serve our patients.
