Kidney tumor - cysts, children, adult benign
Childhood neoplasms
Nephroblastomatosis / nephrogenic rests

Author: Mandolin Ziadie, M.D. (see Authors page)

Revised: 17 January 2017, last major update December 2011

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PubMed Search: Nephroblastomatosis nephrogenic rests kidney

Cite this page: Nephroblastomatosis / nephrogenic rests. PathologyOutlines.com website. http://pathologyoutlines.com/topic/kidneytumornephroblastomatosis.html. Accessed September 19th, 2017.
Definition / general
  • Nephrogenic rests: persistent foci of embryonal cells seen after the period of normal nephrogenesis
  • Nephroblastomatosis: multifocal or diffuse nephrogenic rests
  • May be intralobar or perilobar
Epidemiology
  • 1% of neonatal kidneys; florid cases associated with congenital anomalies and hypertension
  • Intralobar rests have an increased rate of progression to Wilms tumor, are more commonly associated with WT1 mutations, Denys-Drash syndrome and WAGR syndrome
  • Perilobar rests are seen in sporadic tumors and are associated with genetic / epigenetic dysregulation at 11p15 (Clin Cancer Res 2008;14:7635), idiopathic hemihypertrophy and Beckwith-Wiedemann syndrome
Clinical features
  • Precursor lesions of Wilms tumor, seen in 30% - 44% of kidneys resected for Wilms tumor (WT)
Case reports
Treatment
  • Conservative
Gross description
  • May be inapparent on gross examination or appear as nodules / foci of capsular thickening / scar beneath the capsule or in the deep cortex / medulla
Gross images

Images hosted on PathOut server:

Case of the Week #338:

Various images



Images hosted on other servers:

Perilobar nephrogenic nests

Microscopic (histologic) description
  • Tightly packed nests or diffuse sheets of primitive but nonanaplastic blastemal / primitive epithelial cells with scanty stroma
  • No cartilage or primitive mesenchyme
  • May have a sclerosing or hyperplastic pattern
  • Intralobar: randomly distributed throughout cortex and medulla with irregular margins, more stroma than blastema or tubules
  • Perilobar: peripheral with sharply demarcated margins, composed of blastema and tubules with scanty or sclerotic stroma, often solitary
Microscopic (histologic) images

Images hosted on PathOut server:

Intralobar:

Intralobar nephrogenic rest

Neoplastic intralobar rest

Nephroblastomatosis



Perilobar:

Microscopic rests composed of blastemal cells, are termed "incipient" in neonates and "dormant" otherwise

Sclerosing perilobar nephrogenic rest

Focal scarring

Hyperplastic perilobar rest in sclerosing stage


Multifocal hyperplastic perilobar rests

Nearly confluent rind of perilobar rest tissue; thick rind of perilobar tissue

Neoplastic perilobar rest



Case of the Week #338:

Various images

Differential diagnosis
Additional references