Multicystic Dysplastic Kidney (MCDK) is a common cause of palpable abdominal mass
in a neonate, yet reports are few of resultant life-threatening extrinsic compression.
This systematic review is the first to review all known neonatal MCDK cases complicated
by external compression due to mass effect. Our aim is to foster communication about
these unusual cases to inform management of future comparable cases.
This systematic review followed Preferred Reporting Items for Systematic Reviews and
Meta-Analyses (PRISMA) guidelines. Medical Subject Headings (MeSH) were used to search
PubMed through June 8, 2021 as follows: ((((Polycystic Kidney Diseases/complications
[MeSH Terms]) OR (Multicystic Dysplastic Kidney/complications [MeSH Terms])) AND (Humans
[MeSH Terms]) AND (Infant, Newborn [MeSH Terms]) AND (Case Reports [Publication Type])
AND (("multicystic dysplastic kidney") OR ("multicystic kidney")))) OR ((unusual respiratory
distress in newborn [Title]) AND (kidney)) OR (large MCDK). Resulting papers were
screened and included if they reported neonatal MCDK complicated by external compression
by mass effect. Excluded papers lacked an MCDK diagnosis, a neonatal patient, or clear
indication of mass effect. Salient data was extracted from each case for comparison.
Of 51 papers screened, seven met inclusion criteria, presenting eight neonatal MCDK
patients exhibiting varied combinations of symptoms secondary to external compression,
including respiratory distress, gastrointestinal obstruction, and contralateral ureteral
obstruction. All eight cases, ultimately managed with neonatal nephrectomy, had positive
outcomes. Unreported and undiagnosed cases are not included in this review, making
it susceptible to publication bias.
Large neonatal MCDK is typically managed conservatively, however it can be complicated
by external compression due to mass effect. In this scenario, nephrectomy is a reasonable
and definitive treatment. Less invasive management options may exist, e.g., aspiration
with sclerotherapy. Communication about exceptional cases like these should be encouraged
even when outcomes are poor.