Renal pyelocalyceal squamous cell carcinoma in a patient with an ectopic kidney presenting with chronic pyelonephritis: a case report

BACKGROUND: Until now, few cases of pelvis squamous cell carcinoma in various renal anomalies have been reported. To our knowledge, primary squamous cell carcinoma arising from a pelvic ectopic kidney has never been described. In this report, we describe a case of renal pyelocalyceal squamous cell carcinoma in a patient with an ectopic kidney presenting with chronic pyelonephritis. CASE SUMMARY: A 73-year-old Caucasian woman presented to our hospital with pyelonephritis symptoms. Abdominopelvic computed tomography revealed heterogeneous and irregular minimal contrast enhancement in the pelvic ectopic kidney parenchyma. Radiologists reported that the images were consistent with chronic pyelonephritis. A Tc-99m dimercaptosuccinic acid renal scan demonstrated a nonfunctioning right pelvic ectopic kidney. The patient underwent open simple nephrectomy via modified Gibson incision. The whole mass was a distended, saclike structure without any grossly visible renal tissue. Pathological examination showed renal pelvis squamous cell carcinoma 8 cm in diameter infiltrating into the renal capsule and perinephritic fatty tissue. The patient was staged as T4N0M1 renal pelvis squamous cell carcinoma. The patient was being treated in the intensive care unit for respiratory distress on the seventh day after the operation. By the first-month follow-up visit, the patient had died of acute respiratory distress syndrome. CONCLUSIONS: Although rare, renal pelvis squamous cell carcinoma should be considered in the differential diagnosis of a renal mass in patients who have renal anomalies and chronic pyelonephritis.