pathology of tumors of kidney

1. TUMORS OF KIDNEY

2. BENIGN TUMORS

3. Cortical Adenoma
• Multiple
• Associated with chronic pyelonephritis or benign
nephrosclerosis.
Grossly:
• Form tiny nodules up to 3cm in diameter.
• They are encapsulated and white or yellow.

5. Microscopically:
• Composed of tubular cords or papillary structures
projecting into cystic space.
• The cells of the adenoma are usually uniform,
cuboidal with no atypicality or mitosis.
• Larger than 3 cm in diameter are potentially
malignant and metastasising.

7. Oncocytoma
• Benign epithelial tumour arising from collecting ducts.
Grossly:
• Tumour is encapsulated and has variable size.
• Cut section is homogeneous and has characteristic
mahogany-brown or tan colour.
Microscopically:
• Tumour cells are plump with abundant, finely granular,
acidophilic cytoplasm and round nuclei.

10. Angiomyolipoma:
• Hamartoma of the kidney that contains
differentiated tissue element derived from blood
vessels, smooth muscle and fat. Patients of
tuberous sclerosis, a multisystem disease
characterised by skin lesions, CNS and renal
involvement
• Bilateral involvement

12. Mesoblastic nephroma
• Congenital benign tumour
Grossly,
• The tumour resembles a uterine leiomyoma in
having whorled appearance.
Microscopically,
• Shows cellular growth of spindle cells derived
from secondary mesenchyme.

14. Multicystic nephroma
• uncommon tumour of early infancy.
Grossly:
• solitary,
• unilateral well demarcated tumour of varying size.
• Cut surface shows characteristic multilocular
appearance.
Microscopically:
• cysts are lined by tubular epithelium while the stroma
between the cysts contains mesenchymal tissue with
some immature blastemal or abortive tubules.

16. Medullary interstitial cell tumour
• Tiny nodule in the medulla composed of
fibroblast-like cells in hyalinised stroma.

17. Juxtaglomerular tumour or reninoma
• Rare tumour of renal cortex consisting of
sheets of epithelioid cells with many small
blood vessels.
• The tumour secretes excessive quantities of
renin and, thus, the patients are likely to have
hypertension.

19. MALIGNANT TUMORS

20. Adenocarcinoma of Kidney
• Also called Renal cell carcinoma, Hypernephroma,
Grawitz tumor
• Arises from tubular epithelium.
• Common in 50 to 70 years of age
• Male : female = 2 : 1

21. Etiology:

24. Classification:
1. Clear cell
2. Papillary
3. Granular cell
4. Chromophobe
5. Sarcomatoid
6. Collecting duct type

25. MORPHOLOGIC FEATURES:
Grossly:
• Arises from the poles of the kidney as a solitary and
unilateral tumour, more often in the upper pole.
• Large, golden yellow and circumscribed.
• Papillary tumours have grossly visible papillae and
may be multifocal.
• Cut section – large areas of ischaemic necrosis,
cystic change and foci of haemorrhages
• Frequent presence of tumour thrombus in the renal
vein which may extend into the vena cava

27. Histologically:
1. Clear cell type RCC:
• Most common pattern.
• The clear cytoplasm of tumour cells is due to
removal of glycogen and lipid from the cytoplasm
during processing of tissues.
• The tumour cells have a variety of patterns: solid,
trabecular and tubular, separated by delicate
vasculature.
• Majority of clear cell tumours are well
differentiated

28. 2. Papillary type :
• The tumour cells are arranged in papillary pattern
over the fibrovascular stalks.
• The tumour cells are cuboidal with small round
nuclei. Psammoma bodies may be seen.
3. Granular cell type:
• The tumour cells have abundant acidophilic
cytoplasm.
• These tumours have more marked nuclear
pleomorphism, hyperchromatism and cellular
atypia.

29. 4. Chromophobe type :
• This type shows admixture of pale clear cells with
perinuclear halo and acidophilic granular cells.
• The cytoplasm of these tumour cells contains many
vesicles.
5. Sarcomatoid type:
• This is the most anaplastic and poorly differentiated
form.
• The tumour is characterised by whorls of atypical
spindle tumour cells.
6. Collecting duct type :
• This is a rare type that occurs in the medulla.
• Composed of a single layer of cuboidal tumour cells
arranged in tubular and papillary pattern

32. Wilms’ Tumour
• Also called Nephroblastoma
• Embryonic tumour derived from primitive renal
epithelial and mesenchymal components
• Common tumour of young children, seen most
commonly between 1 to 6 years of age with equal
sex incidence.

33. Etiology:
1. A defect in chromosome 11p13 results in abnormal
growth of metanephric blastema without
differentiation into normal tubules and glomeruli.
2. A higher incidence has been seen in monozygotic
twins and cases with family history.
3. Association of Wilms’ tumour with some other
congenital anomalies has been observed, especially of
the genitourinary tract.
4. A few other malignancies are known to have higher
incidence of Wilms’ tumour. These include
osteosarcoma, botyroid sarcoma, retinoblastoma,
neuroblastoma

35. MORPHOLOGIC FEATURES:
Grossly:
• the tumour is usually quite large, spheroidal, replacing most
of the kidney.
• solitary and unilateral rarely occurs as bilateral tumour.
• On cut section – characteristic variegated appearance— soft,
fishflesh-like grey-white to cream-yellow tumour with foci of
necrosis and haemorrhages and grossly identifiable
myxomatous or cartilaginous elements
Microscopically:
• nephroblastoma shows mixture of primitive epithelial and
mesenchymal elements.
• Most of the tumour consists of small, round to spindled,
anaplastic, sarcomatoid tumour cells. In these areas are
present abortive tubules and poorly-formed glomerular
structures.
• Mesenchymal elements such as smooth and skeletal muscle,
cartilage and bone, fat cells and fibrous tissue, may be seen.

38. Clinical Manifestations: