To investigate the incidence, nature, and management of associated ipsilateral genitourinary malformations in children with multicystic dysplastic kidney (MCDK).

In this retrospective study, we analyzed the medical records and imaging studies of 93 patients with MCDK. Patients underwent ultrasonography, voiding cystourethrography, intravenous urography, and radionuclide renal imaging studies during their first month of age.

A diagnosis of MCDK associated with malformation of the ipsilateral internal genitalia was confirmed in 11 patients after birth investigations of prenatal MCDK. Three were diagnosed at 1, 12, and 14 years of age because of epididymitis, pelvic pain associated with amenorrhea, and accidentally during lumbar pain assessment, respectively. The male/female sex ratio was 10:4. The left side was involved in 9 patients. We had 3 cases of Gartner duct persistence, 6 of cystic retrovesical and laterovesical masses with vanishing MCDK, 4 of cystic retrovesical or laterovesical masses with compressive MCDK, and 1 of a blind-ending hemivagina. Nine patients were periodically observed, and four underwent nephroureterectomy. All patients underwent 6-month follow-up examinations with ultrasonography (mean follow-up 6.54 years, range 36 months to 14 years).

Of the 93 patients with MCDK, 14 (15%) had malformations of the ipsilateral internal genitalia. Persistence of seminal cysts in boys and Gartner ducts were encountered even if the MCDK had involuted. These results suggest that follow-up of patients with MCDK should be performed until the end of puberty to detect genitourinary malformations.