Laparoscopic injection of methylene blue in order to discriminate cyst from calyceal divertuculm

Document Type: Case Report


Urology research Center, Tehran University of Medical Sciences, Tehran, Iran




Renal cysts are sacs of fluid with a thin wall usually with no symptoms and have no connection to the renal calyx. Another renal lesion which can be misdiagnosed with cysts is calyceal diverticulum with the connection to the renal calyx. New approach of laparoscopic injection of methylene blue can help surgeon to distinguish renal cysts from calyceal diverticulum in a patient with no double J (Dj/jj).
Case presentation
A 52 years patient with the 15 cm lesion underwent laparoscopic surgery of renal cyst. Surgery was done in the flank position and the peritonoscopy was performed after cyst reveal. At the bottoms of the cyst several small cysts were observed so we inject methylene blue in order to make it clear this lesions was exactly cysts not calyceal diverticulum. When it was proven that there is no leaking of blue color to the renal calyx through catheter. The cyst was revealed and was removed and sent for pathology.
In our study the laparoscopic injection of methylene blue indicated to the no connection with renal calyx so the lesion is definitely renal cysts. So it can be a new approach for distinguishing cyst from calyceal diverticulum.