1. Neoplasms of infancy and childhood

2. Neoplasms of infancy and childhood
Benign>malignant
Incidence of malignancy:1-15 yrs /10,000 /year but leading cause of death after accidents in the West. (developing countries??)
Most malignant tumours in children arise from hematopoietic,nervous and soft tissues (adults –epithelial)

3. Difference between adult & Paed tumours
Association between abnormal development (teratogenesis) & tumour induction.
Prevalence of constitutional genetic abnormalities or syndromes that predispose to cancer
Tendency of malignancy to undergo differentiation
Improved survival

4. Benign tumours Hemangiomas “port wine stain”
Lymphangiomas (cystic hygroma)
Sacrococcygeal teratoma
Naevi

5. Sacrococcygeal teratomas
Germ cell neoplasm
1:40,000 live births
Mass in the sacrum and buttocks
Composed of elements of > 1 germ cell layer.mixture of elements.
Neural origin determines the behaviour
< 2 months-benign.

8. Small,round, blue cell tumours
Primitive appearance (not anaplastic or pleomorphic)
Sheets of small,round,blue cells (with dark nuclei,scant cytoplasm,indistinct borders.)
May show features of organogenesis specific to the tissue of origin.

9. Neuroblastoma Embryonal malignant tumour Neural crest origin
Neoplastic neuroblasts
Site: adrenal medulla &sympathetic ganglia
7-10% of solid paediatric malignancies.
Sporadic occurance.
Rarely familial (bilateral,multifocal)

10. Pathology of neuroblastoma
Site :Paravertebral, Posterior mediastinum, abdomen ,Adrenal 1/3
Gross appearance:
Nodular, of varying size
May be encapsulated or infiltrative
Cut section: grey-tan, soft and friable
Varigated,necrosis,hemorrhage, calcificaton,cystic change

11. Gross appearence of Neuroblastoma.

12. Microscopy of neuroblastoma
Sheets of small,round,blue cells with dark nuclei,scant cytoplasm,indistinct borders.
Mitosis++, Karyorrhectic debris +
Pleomorphism +/-
Homer-Wright rosettes, Neuropil.
Maturation: Schwann cell, stroma &ganglion cell differentiation

13. Microscopy of neuroblastoma

14. Clinical features Abdominal mass, fever Blueberry muffin
Wide metastasis
Secrete catecholamines
Vanillylmandelic acid (VMA)/Homovanillic acid (HVA) screening.

15. Prognosis Stage spread to regional lymph nodes,liver,lungs,bones etc
Age :< 1 yr.
Morphology –gangliocytic differentiation better
MYCN (N myc) gene amplification-worse

17. Retinoblastoma Malignant tumour of the eye in childhood
Neuroepithelial origin –posterior retina
Familial, %, associated with germ line mutation, heritable.
Sporadic:30-40%,somatic gene mutation.
Associated with Rb 1 gene
Secondary malignancy –osteosarcoma

18. RB gene RB gene is on chromosome 13
RB gene function is the most critical checkpoint in the cell cycle and allows the cell to enter from
G1 to S
Tumour supressor gene
If both RB genes are abnormal i.e. mutated or have a missing allele, it permits unregulated cell proliferation.
Knudson’s two-hit hypothesis
People with RB mutations are susceptibe to malignancies especially osteosarcoma

20. Morphology of retinoblastoma

21. Morphology of retinoblastoma
Gross: occular masses.
Microscopy: Sheets of small,round,blue cells with dark nuclei,scant cytoplasm,indistinct borders
Flexner-Wintersteiner rosettes.

22. Behaviour
Spread through optic nerve or to subarachnoid space to CNS, bone, lymph nodes.
Cure with treatment
Spontaneous cure
Second malignancy

24. Wilms’ tumour (Nephroblastoma)
Malignant neoplasm of embryonal nephrogenic elements
Composed of embryonal elements
Prevalence :1:10,000
2-5 yrs
Good prognosis
Associated with congenital malformations
Tumour resembles developing kidney

25. Associated syndromes
WAGR –Wilms tumour, Aniridia, Genitourinary anomalies,mental Retardation
WT 1 gene
Denys-Drash syndrome: Wilms tumour,intersexual disorders,glomerulopathy. WT1 gene
Beckwith –Wiedemann syndrome(BWS) :Wilms tumour, overgrowth, visceromegaly,macroglossia. WT2

26. Cut surface :bulging,pale tan

27. Histopathology of Wilms tumour
Components of Wilms tumour (triphasic)
Blastema
Immature epithelial- abortive tubules ,glomeruli
Immature stroma (mesenchymal)

28. Clinical features 1-3 yrs Unilateral (sporadic),bilateral (familial)
Large abdominal mass
Hematuria
Pain abdomen
Hypertension
Intestinal obstruction
Pulmonary metastasis

29. In conclusion Childhood tumors are different from adult
Small blue round cell tumors
Associated with genetic abnormalities.