Nephroblastoma is a malignant embryonal neoplasm derived from nephrogenic blastemal cells that replicates the histology of developing kidneys and often shows divergent patterns of differentiation.

1. KIDNEY TUMORS

5. PAPILLARY RCC
Subclassification into type 1 and type 2 is no longer recommended.
PRCC has classic morphology historically in type 1 category.
Criteria of foamy histiocytes and psammoma bodies is not required.
Many tumors previously diagnosed as type 2 PRCC now constitute independent entities
 Positive for AMACR, Vimentin, CD10

6. PAPILLARY RCC
Arising from Renal cortex
Low grade tumors RET mutation
High grade tumors CDKN2A
Prognosis favourable

8. CLASSIFICATION OF PAEDIATRIC RENAL TUMORS
OSSIFYING RENAL OF INFANCY
CONGENITAL MESOBLASTIC NEPHROMA
RHABDOID TUMOR OF KIDNEY
CLEAR CELL SARCOMA OF KIDNEY

10. CLEAR CELL SARCOMA KIDNEY
A/K/A Bone metastasizing renal tumor of childhood.
BCOR mutations or YWHAE:NUTM2 gene fusion.
Centred in the renal medulla.
MC age group is less than 3yrs.

11. CLEAR CELL SARCOMA KIDNEY
Gross- Homogenous, lobular with light pink soft areas.
Many histological patterns.
Ovoid tumour cells with nuclear and/or cytoplasmic clearing at least focally, distinctive
arborizing fibrovascular septa

13. ADULT CYSTIC NEPHROMA
A/K/A Multilocular cystic nephroma.
Benign neoplasm in adult
Women> Men
Hormonal imbalance

14. ADULT CYSTIC NEPHROMA
Well circumscribed globular mass with fibrous capsule.
Multiple non communicating cysts without any solid areas.
M/E cyst wall lined by cuboidal or flattened epithelium with clear cytoplasm resembling ovarian
stroma.

16. PAEDIATRIC CYSTIC NEPHROMA
Almost exclusively occurs in children with higher prevalence in males
Similar macroscopic and microscopic findings
Most harbor DICER1 mutations.

17. MEST
MIXED EPITHELIALAND STROMAL TUMOR
Comprises of solid and cystic or completely solid areas.
The epithelial component is usually scattered in the stroma or closely clustered. Small cysts
containing eosinophilic material reminiscent of thyroid follicles, complex branching tubules,
phyllodes-type architecture, and papillary structures have been seen.

18. WILMS TUMOR
Nephroblastoma is a malignant embryonal neoplasm derived
from nephrogenic blastemal cells that replicates the histology
of developing kidneys and often shows divergent patterns of
differentiation.