Nephrectomy for multicystic dysplastic kidney and renal hypodysplasia in children: where do we stand?

OBJECTIVES: Little is reported in literature regarding correct management of benign lesions of the kidney. The aim of our study is to present a series of total and partial nephrectomies performed in the last 5 years and to discuss indications. MATERIALS AND METHODS: Patients with benign lesions who underwent nephrectomy and partial nephrectomy at our institution in the period 2003-2008 were retrospectively included in the study. Notes were carefully reviewed and demographic data, symptoms onset, preoperative diagnosis, investigations, medical and/or surgical treatment, postoperative complications and definitive histological reports were collected. RESULTS: Forty procedures were performed. Twelve patients were preoperatively diagnosed of having multicystic dysplastic kidney (MCDK), which was confirmed in 10, whereas the remaining 28 patients of having severe dysplasia or hypodysplasia. Thirty-four patients underwent total nephrectomy, six underwent partial nephrectomy. Histopathological analysis confirmed segmental or complete abnormalities of the involved kidney in all cases. No malignancies were detected. DISCUSSION: Our study confirmed the extremely low malignancy rate of MCDK and hypodysplastic kidneys. The 20% mismatch of pre- and post-operative diagnosis suggests a common aetiology and shared therapeutic strategies for MCDK and hypodysplasia. At present, there is no consensus regarding correct indications for nephrectomy in paediatric age. As nephrectomy seems not to provide any advantage over preservation, but surgical and anesthesiological risks, we should be prudent in preserving every asymptomatic poorly or non-functioning kidneys maintaining a strict follow-up. Randomised controlled studies on larger multicentric series are strongly warranted to define this topic.