Intestinal metaplasia of ureter and renal pelvis: a case report

Abstract

Objective: Transformation of the urothelium to the intestinal type of epithelium is rare in the pelvis with very few cases reported in the literature. The present study reports partial intestinal metaplasia of the renal pelvis with residual urothelium and subsequent focal stromal osseous metaplastic changes in a 61-year-old man with previous clinical suspicion of renal tumour. Material and Methods: Left-sided nephrectomy was undertaken. The gross examination revealed papillomatous proliferation in the ureteropelvic junction measuring 1x0.8x0.3cm. On selected samples immunohistochemical analysis with Actin, CK7, CK20, CDX2 and Ki67 was made. Results: The microscopic examination showed striking focal replacement of transitional epithelium of the ureteropelvic junction, with intestinal type of epithelium. The intestinal glands were lined by tall columnar epithelium with numerous goblet cells. Immunohistochemistry of the metaplastic epithelium revealed positive expression for CK7 with focal expression for CK20, CDX2 and low Ki67 index. Conclusions: Although intestinal metaplasia is frequently encountered in the urinary bladder, it is very rare to find such metaplasia in upper urinary tract including renal pelvis and ureter. In this case metaplastic changes did not progress to adenocarcinoma which indicates that intestinal metaplasia is not always associated with malignancy.