|
The tumour
stage is the critical parameter for treatment, and its accurate
assignment is one of the most important and challenging duties
of the pathologist.
Renal tumours
of childhood are usually very large, and often it is very difficult
to assess their relationship with normal anatomical structures such
as the renal capsule and the renal hilum.
The
tumours are usually soft and friable resulting in difficulties
during sampling and histological evaluation, such as displacement
artefacts ("carry-over") and capsular retraction.
The following procedure is recommended for handling the nephrectomy
specimen:
1. Specimens
should be received intact by the pathologist. The common surgical
practice of bisecting in the operating theatre should be strongly
discouraged.
2. The surface
of the specimen should be inked (at least in areas of possible
tumour infiltration).
3. After the
ink is dry, an initial incision can be made to obtain samples
for cytogenetic, molecular biological and ultrastructural studies.
This incision should display the relationship of the tumour to the
kidney and renal hilum.
4. Further
parallel incisions can be made and the specimen left to fix
overnight. Never strip the capsule!
5. Tumour
sampling should be extensive (at least 1 block per cm of tumour
diameter), and the site of each block carefully documented (on
a drawing, or photograph). It is important to sample not only
central areas of the tumour but also its periphery, the tumour-kidney
interface, the renal hilum and its structures. Finally, the renal
background parenchyma should be sampled.
Staging should
generally be done according to the criteria shown below.
Stage Definitions
Stage 1 Tumour
confined to the kidney and completely resected
(no penetration of the renal capsule ; no invasion
of
renal hilum soft tissues or vessels)
Stage 2 Tumour
extends beyond kidney but completely resected
(renal capsule penetrated but resection margins
clear;
tumour present in the renal hilum fat or vessels,
but the
medial resection margin clear)
Stage 3 Gross
residual tumour, involved resection margins; or
involved regional lymph nodes.
Stage 4 Hematogenous
metastases, or lymph nodes beyond
local regional drainage area (e.g. mediastinal
nodes)
Stage 5 Bilateral
renal tumours (But note: each tumour should
be substaged separately).
Visit:
Paediatric Pathology Online
; Paediatric Renal Tumours
;
Wilms’ tumour (nephroblastoma)
;
Wilms' tumour related lesions
;
Mesoblastic Nephroma
;
Nephrogenic
rests
;
Clear Cell Sarcoma of the Kidney
;
Malignant Rhabdoid Tumour
of Kidney
;
Immunohistochemistry and Molecular Biology of Wilms'
Tumour and related lesions.
|
