Dermoid Cyst in a Multicystic Dysplastic Kidney: A Case Report and Literature Review.

Most multicystic dysplastic kidneys (MCDKs) are discovered prenatally. There is no consensus regarding initial workup and appropriate follow-up. We present a 9-year-old female who was fetally diagnosed with a MCDK and without follow-up returned with an 18-cm multicystic mass. The patient underwent laparoscopic nephrectomy. Final pathology revealed a dermoid cyst arising in a pediatric kidney, which to our knowledge has not been previously described. Patients with MCDK have hypertension as a possible sequela and possible reflux to their functioning kidney. Voiding cystourethrogram seems reasonable initially, and renal ultrasound is ideally noninvasive. Focused clinical awareness of the solitary kidney is important.