Intestinal metaplasia of the renal pelvis: A case report and literature review.

Metaplastic changes in the renal pelvis are infrequent and may be malignant transformations to adenocarcinoma. The current study reports a case of intestinal metaplasia in the right renal pelvis, which was associated with staghorn calculi, in a 56-year-old female. The patient underwent a percutaneous nephrolithotomy. Immunohistochemical assessment of the mucosa of the renal pelvis revealed the positive expression of carcinoembryonic antigen, cytokeratin (CK)-7 and CK20, but negative expression for CK5/6 and vimentin. Furthermore, Ki67 expression was diffusely positive, while p53 was negative. Unlike other previously reported cases, the patient opted for active surveillance as opposed to radical nephrectomy, following the removal of the calculi. No evidence of progression was observed after three years of follow-up. Therefore, etiological treatment and close follow-up may be a suitable treatment option for localized intestinal metaplasia.