N Vasdev, A Thwaini, G Walker, G Suresh
malignant melanoma, metastasis, urinary bladder
N Vasdev, A Thwaini, G Walker, G Suresh. Metastatic Malignant Melanoma of the Urinary Bladder. The Internet Journal of Urology. 2009 Volume 6 Number 2.
We report on a case of Malignant Melanoma (MM), a rare tumour type with metastasis to the urinary bladder. To our knowledge, there have been nine cases so far reported in the literature. We present the clinical presentation, investigations and treatment of this uncommon presentation.
A 58 year old, previously healthy male presented in February 2004 with an eight-week history of a painless soft tissue mass lesion on the right buttock, going into the right side of the perineum. There were no associated symptoms.
His clinical examination confirmed a 5x5 cm soft mobile mass, non-tender, with no regional lymph nodes. His investigations were normal apart from a pelvic MRI, which surprisingly showed a large soft tissue mass lesion on the left side of the urinary bladder (figures1&2).
Figure 1& 2: MRI showing radiological features of Malignant Melanoma of urinary bladder.
Cystoscopy showed a solid mass lesion with normal overlying mucosa. He subsequently underwent TURBT and excisional biopsy of the buttock lesion. Histology confirmed Malignant Melanoma, with metastasis to the urinary bladder (figures 3&4).
Figures 3&4: Histopathological confirmation of Malignant Melanoma of the Urinary Bladder.
He then underwent partial cystectomy and excision of an enlarged mesenteric lymph node introperatively, which turned out to be involved. Four courses of systemic chemotherapy in the form of Tropisetron 5mg, dexamethasone 8mg, doxorubicin 150mg and Dacarbazine 1700mg. were started. Since, he has been under regular follow up with no evidence of tumour metastasis.
Most of the secondary malignant melanomas of the urinary bladder are asymptomatic. However, some may present with irritative lower urinary tract symptoms and/or haematuria [1, 2]
Malignant Melanoma is known to metastasize to different organs, including stomach, oesophagus and uncommonly to the urinary bladder as one of the rare sites of secondaries. [3 to10]
Time of presentation: secondaries of MM could present simultaneously or after a period of time, which could be years prior to its clinical presentation .
The treatment of this rare condition is still controversial. However, the aim is symptomatic relief, if this is the case. This is in the form of endoscopic management and/or systemic chemotherapy. In addition, reports have been made on intralesional injection of BCG treatment of the disease, with good early results. However, the long-term results are not available .
In a patient with malignant melanoma, secondary metastasis to the urinary bladder should be considered while looking for staging of the primary tumour.
List of Abbreviations
Malignant Melanoma (MM)