Pathological findings of ketamine ureteritis

A 35-year-old man with a history of ketamine abuse for 2 years came to our outpatient clinic with dysuria and urinary frequency for 2 weeks. Acute urinary retention and gross hematuria occurred the next day after cystoscopy and hydrodistention of the bladder. He was admitted for blood clot evacuation under the impression of ketamine cystitis with blood clot tamponade in the bladder. He had repeated lower urinary tract symptoms and gross hematuria afterward. Six months later, an intravenous urogram performed for left flank pain showed left hydronephrosis and hydroureter with stenosis in the left distal ureter (Fig. 1). He underwent an ureteroscopic optic ureterotomy and placement of a double-J stent. A ureteroscopic biopsy from the left ureter was performed to exclude the possibility of a tumor. The biopsy specimen from the left ureter consisted of two reddish-brown soft-tissue fragments measuring up to 0.9 0.2 0.1 cm3. Microscopic examination of the histologic sections revealed denudation of most of the overlying urothelium, with reactive regenerative changes in the residual urothelium that showed mildly hyperchromatic nuclei (Fig. 2). The regenerative epithelium stained positive for CK7 and negative for p53 on immunohistochemical stains. In addition, there was stromal edema, diffuse chronic inflammatory infiltration, and active granulation tissue in the subepithelial connective tissue. The granulation tissue also extended into the muscle layer. The inflammatory infiltrates were mainly composed of lymphocytes and only a few