Extracorporeal shockwave lithotripsy: urine cytology findings

To describe the urine cytology findings before and after stone therapy with extracorporeal shock wave lithotripsy (ESWL) and discuss its importance.

The study consisted of 100 patients with a urinary tract stone (79 renal pelvic stones and 21 upper ureteric stones), 74 were male and 26 were female. The ages ranged 30-55 years. The average duration of symptoms was 3-8 years. The size of the stones varied from case to case ranging from 10.2 to 40 mm. Urine samples were obtained on three consecutive days before and after lithotripsy. The smears were stained by the Papanicolaou method.

The smears before lithotripsy revealed a few red blood cells, inflammatory cells, epithelial cells and crystals (calcium oxalate, uric acid and triple phosphate). Atypical malignant looking cells and epithelial cell clusters were not noticed. After lithotripsy, the urine samples were examined at different periods, 24 hours, 2 weeks, 1 month, 2 months and 3 months. The smears revealed papillary clusters in all 100 patients within 24 hours and were always associated with inflammation. Atypical malignant looking cells appeared later, within 1-2 months in 21 patients, and were associated with inflammation (19 patients), RBC, crystals and papillary clusters. Most of the papillary clusters and atypical malignant looking cells disappeared before 3 months.

The epithelial cell clusters and atypical cells were seen in urine smears after ESWL. Without knowing the previous history these findings can be confused with urothelial neoplasms.