Papillary renal carcinoma arising in an ectopic native kidney and status after renal transplant: a report of a unique case and review of the literature

Abstract

Renal ectopia is an uncommon developmental defect of upper urinary tract. Except for hydronephrosis and urinary calculus formation, it is believed that ectopic kidneys are not more susceptible to diseases compared to the normally positioned kidneys. Primary renal carcinoma in ectopic kidneys is rarely observed. Our literature review identified eight cases in nontransplanted patients; seven were clear-cell carcinoma and one was papillary renal carcinoma. On the other hand, native kidneys of renal transplant patients are fifteen times more likely to develop renal carcinoma than those of nontransplanted patients. Renal malignancy has never been reported in native ectopic kidneys of transplant recipients. We report the first case of a papillary renal carcinoma in a native ectopic kidney of a 30 year-old female, six-year status after renal transplantation.

Figure 1

Histological and immunohistochemical features of the papillary renal cell carcinoma. Low-power view shows the papillary structures with fibrovascular cores ((a), original magnification 100x). The columnar neoplastic cells have finely granular eosinophilic cytoplasm, bland nuclear feature. Foamy histiocytes are seen within the fibrovascular cores ((b), original magnification 400x). The neoplastic cells are positive for CK7 (c), vimentin (d), PAX-2 (e), and AMACR (f) (original magnification 400x).