“…Several medications have been implicated as well, including oral contraceptives, retinoids, antiretrovirals and antineoplastic drugs. 1 , 5 In the previously reported mucosal urologic cases, potential contributing factors included a recent history of ureteroscopy for urolithiasis 3 and recent chemotherapy for pancreatic cancer. 2 In the case presented here, no clear etiology was found, as this pediatric patient was otherwise healthy, was on no medications, and had not had any urologic instrumentation.…”