Renal Diseases
Renal cysts and
Tumors
CYSTIC DISEASES OF
THE KIDNEY
 Fluid
filled spaces within the kidney
 May involve cortex or medulla or both
 May be unilateral or bilateral
 May be unilocular or multilocular
 May be congenital or acquired
 May be sporadic or genetically determined
 Clinical significance may be trivial or grave
CLASSIFICATIONS OF RENAL CYSTIC
DISEASES
 Polycystic
kidney diseases:
1. Autosomal recessive (ARPKD)
classic infantile polycystic disease
with congenital hepatic fibrosis
2. Autosomal dominant (ADPKD)
 Simple renal cysts
 Acquired renal cystic disease
Autosomal Recessive Polycystic
Kidney Disease ( ARPKD )
Rare, 1:6-14000 live births
 Abnormal gene located on chromosome 6p21
 May be still born or neonatal death due to
pulmonary insufficiency
 Progressive renal failure
 Low specific gravity, mild proteinuria, urine
concentrating defect, anemia, hypertension CCF
 Bilaterally symmetrical enlargement of kidneys
 Smooth surface with innumerable 1-2 mm cysts
 Diffuse fusiform dilatation of the collecting ducts

ARPKD ( Cont. )
Enlarged but normally shaped pelvi-calyceal system
 Normal reniform shape complete with fetal lobation
& normal sized (undilated) ureter
 Normal glomeruli and tubules
 Normal interstitium and no dysplasia
 Congenital hepatic fibrosis is almost always present
 Normal numbers of nephrons, no interstitial
fibrosis and no dysplasia

Autosomal Dominant Polycystic
Kidney Disease (ADPKD )
World wide, 1:1000 in general population
 Accounting for 6% of patients in dialysis and
transplant program
 Abnormal gene on short arm of chromosome 16
i.e. 16p13.3(PKD-1). 4q12-22(PKD-2), 3rd locus
found
 Present in 3rd-5th decade
 Dull loin pain, flank masses. azotemia, positive
family history, hypertension, hematuria, colic etc.
 Prograssive renal failure anemia &  GFR,  Ur
& Cr

ADPKD (CONT.)
 Associated
cysts in liver of biliary type, in
pancreas (10%), spleen,thyroid & seminal
vesicle
 Vascular anomalies including Berry
aneurysms(33%), aortic aneurysm, aortic root
dilatation and mitral valve prolapse
 Diverticular disease of the colon (80%)
ADPKD- Pathological Features
Bilaterally enlarged kidneys (up to 4000 gms)
 Diffuse cystic (1-2% cystic nephrons) change with
uninvolved intervening parenchyma
 Varying sized, numerous to innumerable generally
spherical unilocular cysts, distributed in cortex and
medulla obscuring normal reniform shape and
corticomedullary junction, containing yellowish to
turbid to brown to black colored fluid
 Distorted pelvi-calyceal system
 Cysts arising from any part of nephron or collecting
duct

ADPKD- PATHOLOGICAL FEATURES
 Cysts
lined by single layer of cuboidal
epithelium
 Neoplastic change - uncommon
Simple Renal Cysts
 Extremely
common as age advances
 Incompletely understood pathogenesis
 Commonly associated with scarred kidneys
 Asymptomatic with normal renal function
 May be solitary/multiple/unilateral/bilateral
 Generally unilocular, round to oval of varying
sizes
SIMPLE RENAL CYSTS (Cont.)
 Arises
as dilated tubules or collecting ducts
 Thin, translucent fibrous wall containing clear
or amber colored serous fluid
ACQUIRED RENAL CYSTIC DISEASE
 Secondary
to end-stage renal disease as well
as prolonged dialysis ( 9 months -7 yrs.)
 Kidneys are generally small but may be
normal or even enlarged
 Common in cortex
 Seems to be arising in either proximal or
distal tubules
 Neoplastic change are common
RENAL TUMOURS
 In
infants and children :
• Nephroblastoma ( Wilms’ tumour )
 In adults :
• Renal cell carcinoma
• Renal cell adenoma
• Renal oncocytoma
NEPHROBLASTOMA ( Wilms’ tumour )

Embryonal tumour arising from nephrogenic
blastemal cells
• can differentiate in to several cell lines - blastemal,
epithelial and stromal
• many replicate developing kidneys
Common in young children / uncommon in
neonates and infants
 90% in < 6yrs. old ( mean: 3yrs. in boys and 3.5yrs.
in girls )

NEPHROBLASTOMA
Etiology and Pathogenesis
 Generally
unknown
 World wide i.e. … No environmental factors
 Variable incidence in racial groups :
• blacks> whites> Orientals
 Familial
tendencies: 1% autosomal dominant
with variable penetrance & expressivity
 Genetic predispositions
• WT-1 gene (11p13); WT-2 gene (11p15.5)
NEPHROBLASTOMA
Clinical Features
 Most
common genitourinary cancer
 Age: 1-3yrs., 98% in <10yrs
 Abdominal mass, pain, & hematuria
 Usually unicentric, may be multicentric (7%)
or bilateral (5%)
 Imaging technique to reveal smaller lesions
 No specific tumor markers identified
NEPHROBLASTOMA
Pathologic findings (gross)
 Usually
solitary, sharply (well) defined
masses with pseudocapsule
 Variable size & weight (60-6350 gms.
with a mean of 550 gms.)
 Uniform, pale gray to tan, divided by
prominent fibrous septa in to lobules
 May be cystic, hemorrhagic or necrotic
 No specific location
NEPHROBLASTOMA
Microscopic findings
 Generally
triphasic pattern :
• blastemal, epithelial and stromal cell type
 may
contains heterologous elements
 “favorable” or “unfavorable” histology
on the bases of nuclear anaplasia i.e. . . .
• marked nuclear enlargement (3x)
• abnormal mitoses i.e. . . . increased DNA
NEPHROBLASTOMA - Spread
 Local
 Regional
 Distant
• lungs
• liver
:
i.e. . . lymphatic
NEPHROBLASTOMA
prognosis and treatment
 Depends
upon :
• stage, age and histology
 Surgery with chemotherapy for :
• stage I & II with favorable histology
• surgery with chemotherapy and
radiotherapy for higher stages and
unfavorable histology
RENAL CELL CARCINOMA
 Hypernephroma
/ Grawitz’s tumour
 3% of all adult malignancies
 world wide, no racial predispositions
 M:F = 1.6:1, 6th decade (mean 55 yrs)
 seems to be arising from mature renal
tubules
 tobacco - smoked / chewed
RENAL CELL CARCINOMA ( Cont. )
 Chromosomal
abnormalities :
• 3p13 - clear or granular cell type
• trisomy 17/ tri-or tetrasomy 7 - papillary
type
 Rare familial association
 Associated with acquired cysts and / or in
patients on chronic hemodialysis
RENAL CELL CARCINOMA
Clinical Features & Diagnosis
 classic
triad :
• hematuria, flank pain and abdominal mass
 may be clinically occult, 30% presents with
metastatic lesion
 Polycythemia due to erythropoietin
 constitutional symptoms
 imaging techniques - useful
RENAL CELL CARCINOMA
mode of dissemination
Direct
extension
Vascular
Lymphatic
Lungs, lymph nodes, liver, bone
brain, skin etc.
RENAL CELL CARCINOMA
prognosis
 Influenced
by multiple factors :
• tumour size
• infiltrative margins
• histological type
• tumour stage - most important
 Can be expressed in terms of histological
types
RENAL CELL ADENOMA
 Incidental
findings at autopsy (22%)
 Well demarcated, unencapsulated
 Pale yellow-gray, discrete cortical mass
 Up to 2 cms. in maximum dimension