[Acute Stone Street Formation Due to Spontaneous Emptying of Calyceal Diverticulum].

A 73-year-old woman presented with a chief complaint of left-sided abdominal pain from the time of waking. She had a calcified lesion in the left kidney for at least 4 years, but as she was asymptomatic, a detailed examination was not performed. Owing to the sudden onset of left-sided abdominal pain, she visited her local emergency department, where left renal and ureteral stones were identified on computed tomography. She was then referred to our department. A diagnosis of calyceal diverticulum stone disease and associated stone street was made on the basis of retrograde urography and other tests. Transurethral lithotripsy was performed under general anesthesia. A soft ureteroscope was successfully inserted into the diverticulum, where numerous stones were found. After three sessions of transurethral lithotripsy, all stones were removed. The main stone component was calcium oxalate. In this case, it was considered that the 4-year-duration nephrocalcific lesion (calyceal diverticular stones) had drained rapidly from the diverticulum to form a stone street.