Renal keratinizing desquamative metaplasia (KDSM) is an uncommon condition that can mimic kidney stone symptoms, including renal colic. Typically, treatment is conservative, focusing on pain management and regular imaging. Surgical intervention is generally reserved for cases where symptoms do not respond to these measures. This report discusses a case where a percutaneous nephrolithotomy (PCNL) approach was employed to endoscopically remove KDSM tissue from the renal pelvis using hydrodissection. The patient, a 58-year-old male with hypertension and diabetes, had a history of recurrent renal colic and passed “skin-like” material in his urine. Despite prior treatments, including PCNL, extracorporeal shockwave lithotripsy, and multiple ureteroscopies with an external urologist, the patient experienced persistent symptoms due to extensive KDSM in the right renal pelvis. A CT scan revealed partially calcified material within the affected region, leading to a scheduled PCNL for KDSM removal.
During surgery, the patient was positioned prone, and access was achieved using ultrasound guidance into a posterior interpolar calyx. The KDSM tissue was visible in the lower renal pelvis, but its flat nature prevented easy removal with a standard duckbill grasper. A 350 mm Deflux needle was introduced through the nephroscope, and small saline injections were administered to lift the KDSM tissue off the subepithelial layer. This hydro dissection technique enabled better access for the grasper to remove the elevated tissue in sections around the renal pelvis circumference. The procedure was successful, and the patient recovered well, being discharged on the first postoperative day. At the 8-week follow-up, he reported no pain or further symptoms. This case illustrates that KDSM, though rare, can be effectively managed with the innovative use of a Deflux needle for hydro dissection during PCNL, providing a viable solution for cases unresponsive to conservative treatment.
