Spectrum of renal pathology in adult patients with congenital renal anomalies-a series from a tertiary cancer center.

Congenital renal anomalies (CRAs) detected in adults include horseshoe kidney (HK), crossed renal ectopia, and malrotation. Congenital renal anomalies are rare, and renal lesions associated with CRA are rarer. Thirteen patients (11 men and 2 women) were referred to our center with renal masses in the context of CRAs, which included HK (10 cases), crossed renal ectopia (2 cases), and a pelvic kidney (1 case). The mean age at diagnosis was 60 years (37-76 years). All patients were treated with open surgery; 10, partial nephrectomies; 4, radical nephrectomies; and 1, nephroureterectomy with division of the renal isthmus. Pathology ranged from benign (simple cortical cysts, chronic pyelonephritis with secondary hydronephrosis) to malignant (12 cases of renal cell carcinomas [RCCs] and 1 case of urothelial carcinoma). Two patients of HKs presented with bilateral renal masses. The size of the RCC ranged from 2.5 to 13 cm. There were 11 cases of clear cell RCC, 1 case of papillary RCC (type 1), and 1 case of urothelial carcinoma. All the cases of RCC had negative surgical margins. Follow-up available in all patients ranged from 1 month up to 49 months. None of the patients developed any locoregional recurrences or distant metastases. In this patient cohort, the most common congenital anomaly associated with RCC is HK. All tumors behaved in an indolent fashion with prognosis related to pathologic tumor stage. Partial nephrectomy is a safe and effective procedure in appropriately selected patients.