[Mucin-producing cystadenoma (borderline malignancy) of the renal pelvis and ureter. A case report].

The patient was a 63-year-old women who visited our hospital with the chief complaints of swelling, chills, fever and right lumbago. Fifteen years ago, she received surgical exploration for right renal stones at another department of urology. A large, soft and round kidney was palpable from the right upper quadrant of abdomen to the right lower abdomen. The parenchyma of the right kidney was thinned and inside the kidney there was a huge amount of yellowish mucin. The histological diagnosis was mucin-producing cyst-adenoma (borderline malignancy) of the renal pelvis and ureter. Mucin-producing cystadenoma of the renal pelvis and ureter origin was very rare, and only 4 similar cases to our patient were so far reported.