1. Renal Diseases
Renal cysts and Tumors

2. 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

3. 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

4. Autosomal Recessive Polycystic Kidney Disease ( ARPKD )
Rare, 1: 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

5. 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

9. 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

10. 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%)

11. 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

12. ADPKD- PATHOLOGICAL FEATURES
Cysts lined by single layer of cuboidal epithelium
Neoplastic change - uncommon

15. 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

16. SIMPLE RENAL CYSTS (Cont.)
Arises as dilated tubules or collecting ducts
Thin, translucent fibrous wall containing clear or amber colored serous fluid

19. 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

21. RENAL TUMOURS In infants and children :
Nephroblastoma ( Wilms’ tumour )
In adults :
Renal cell carcinoma
Renal cell adenoma
Renal oncocytoma

22. 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 )

23. 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)

24. 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

25. NEPHROBLASTOMA Pathologic findings (gross)
Usually solitary, sharply (well) defined masses with pseudocapsule
Variable size & weight ( 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

27. 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

28. NEPHROBLASTOMA - Spread
Local
Regional i.e. . . lymphatic
Distant :
lungs
liver

29. 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

30. 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

31. 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

32. 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

38. RENAL CELL CARCINOMA mode of dissemination
Direct extension
Vascular
Lymphatic
Lungs, lymph nodes, liver, bone brain, skin etc.

39. 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

40. RENAL CELL ADENOMA Incidental findings at autopsy (22%)
Well demarcated, unencapsulated
Pale yellow-gray, discrete cortical mass
Up to 2 cms. in maximum dimension