Metastasizing renal cell carcinoma developing in a congenital ectopic and dysplastic kidney.

UNLABELLED: We present the first case of a metastasizing renal cell carcinoma arising within a partially regressed multicystic dysplastic and ectopic left kidney in a 34-year-old patient. Despite nephrectomy and adjuvant immunotherapy, the patient died 4 months after diagnosis. Even though a recent systematic review found no evidence to support any of the different modalities for following up children with MCKD by ultrasound (Oxford Centre for Evidence-Based Medicine, LEVEL OF EVIDENCE: 3a), our case supports the contrary and we emphasize that an annual control could be an important diagnostic choice ( LEVEL OF EVIDENCE: 4).