Mucinous cystadenocarcinoma of renal pelvis presenting as pyonephrosis.

Mucinous cystadenocarcinoma of renal pelvis is a rare epithelial tumor with poor prognosis. It is postulated to arise from metaplastic glandular mucosa in response to chronic irritation, and comprises less than 0.3% of total renal pelvic tumors. We present this case of a tumor noted in a 45-year-old lady that was diagnosed as mucinous cystadenocarcinoma on histological examination after radical nephrectomy. The patient is remaining well over a follow-up of three months.