Doctors in southwestern China thought they were looking at a large but ordinary kidney cyst. Then, after they placed a thin tube to relieve a blocked kidney, the cyst began to shrink. Simple cysts are not supposed to do that, and the change exposed what had been hiding in plain sight: a giant pouch connected to the kidney's drainage system, sealed off by a stone.
The case, reported by urologists at the Fourth Affiliated Hospital of Dali University in Chuxiong, Yunnan province, was published online August 21 in the International Journal of Surgery Case Reports. It describes a 69-year-old man with a 9-centimeter giant calyceal diverticulum.
