Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

the neoplasm from the adjacent rest
and normal kidney.
Intralobar nephrogenic rests
In contrast to PLNRs, ILNRs are typically
located in the central areas of the
lobe, are poorly circumscribed and
composed of stromal elements as well
as epithelial tubules. Like PLNRs,
ILNRs may be dormant, regress, or
undergo hyperplasia. Nephroblastoma
developing with ILNRs are often separated
from the underlying rest by a peritumoural
fibrous pseudocapsule.
Prognosis and predictive factors
In diffuse hyperplastic nephroblastomatosis,
the risk for the development of
nephroblastoma is extraordinarily high.
Chemotherapy is commonly utilized
because it reduces the compressive burden
of nephroblastic tissue, which enables
normalization of renal function, and
reduces the number of proliferating cells
that may develop a clonal transformation.
There is a high risk of developing multiple
nephroblastomas as well as anaplastic
nephroblastomas. Therefore, their tumours
must be carefully watched and monitored
for responsiveness to therapy.
In the management of patients with
nephroblastomatosis, imaging screening
by serial ultrasonography and CT scans
enables an early detection of nephroblastoma
{191}. Prompt therapy can minimize
the amount of native kidney that requires
surgical excision (nephron sparing
approach), thereby maximizing the preservation
of renal function.
Fig. 1.74 Hyperplasia within a large perilobar nephrogenic rest.
A
B
Fig. 1.75 Intralobar nephrogenic rest. A Ill defined proliferation of embryonal cells and intermingling with the
native kidney. B Hyperplastic blastemal cells proliferating within the rest intermingling with the native kidney.
54 Tumours of the kidney