MCDK not excluded by virtue of function on renal scan.

INTRODUCTION: The conservative management of multicystic dysplastic kidneys (MCDK) has been very successful, largely due to advances in diagnostic imaging. Classically, MCDK is described as a non-functioning cystic renal mass. However, we noticed that the increasing sensitivity of renal scans is able to demonstrate function in MCDK that previously would not have been detected. METHODS: We describe eight cases of MCDK with elements of function on renal scan, and their follow up. RESULTS AND CONCLUSIONS: One half (4/8) of these children underwent nephrectomy, and histology was consistent with MCDK. The remaining 4/8 were successfully followed to radiographic involution, without any complications. Therefore, we believe that minimal function on nuclear scintigraphy does not preclude the diagnosis of MCDK, and is yet another adjustment in our understanding of this entity.