A multicystic dysplastic kidney (MCDK) is a congenital abnormality in which the kidney fails to develop normally and consists of multiple non-communicating cysts of varying sizes, with no functioning renal tissue. It is distinguished from hydronephrosis by the absence of a normal central pelvicalyceal system. On prenatal ultrasound, MCDK is detected as a cluster of cysts of different sizes in place of a normal kidney without the typical echogenic central sinus. MCDK is generally non-functional, and affected kidneys usually regress or involute over time. Most MCDKs are managed conservatively with observation, though rare complications may necessitate nephrectomy. The prognosis depends on whether there is normal function in the contralateral kidney.
Sonography Term