Significance of pigmented urothelial and non-urothelial cells in voided urine specimens: A case report and review.

We present a case of metastatic malignant melanoma to the urinary bladder diagnosed on a voided urinary cytology specimen in a patient who visited the emergency department complaining of right flank pain, and dark urine. The patient reported having previous episodes of kidney stones. Additionally, more detailed clinical history obtained after the cytological diagnosis, revealed a previous excision of malignant melanoma on the back 10 years ago.