Primary adenocarcinoma of renal pelvis or ureter: an uncommon histopathological entity seen in three cases

Abstract
Background
Primary adenocarcinoma of renal pelvis or ureter is rarest (< 1%) among all urothelial tumors. Regrettably, no characteristic symptoms, radiological features and treatment for this tumor are reported. We report three cases of adenocarcinoma of renal pelvis and ureter.

Case presentation
Case 1 had grossly hydronephrotic non-functional right kidney and underwent percutaneous nephrostomy followed by laparoscopic simple nephrectomy. Incidentally, histopathological examination reported adenocarcinoma of renal pelvis. Whole-body positron emission tomography-CT (PET-CT) ruled out malignancy at other sites. Patient refused adjuvant chemotherapy. Case 2 presented with previous history of right pyelolithotomy, right ureteroscopic lithotripsy and right flank pain with intermittent discharge via previous percutaneous site. On biochemical and radiological investigations, right poorly functioning pyonephrotic kidney was confirmed. Patient underwent right open nephrectomy which incidentally reported adenocarcinoma of renal pelvis. Patient is disease-free at 18 months of follow-up. Case 3 had left ureteric wall thickening on CT scan when evaluated for hematuria. Ureteroscopic-guided biopsy showed villous adenoma. Laparoscopic left nephroureterectomy with bladder cuff excision specimen showed well-differentiated adenocarcinoma in ureter with extension into periureteric fat. Patient died 32 months after surgery.

Conclusion
Primary adenocarcinoma of renal pelvis or ureter is very rare and urologists should suspect it in patients with mucinous material in nephrostomy tube. We should have a low threshold for performing radical nephrectomy with complete ureterectomy in these unusual cases to improve the prognosis.