w5 lecuture 11: tumour lesions childhood

Question 1

name the 2 developmental tumours?

Answer 1

• Hamartoma
• choristoma

Question 2

what is hamartoma?

Answer 2

tumour like malformation in which tissues of a certain organ are organised haphazardly, usually with an excess of 1 or more components

e.g chondroid hamartoma of lung
hemangioma

Question 3

what is choristoma?

Answer 3

Tumour-like mass of normal non-neoplastic ECTOPIC tissue in an abnormal
location
- e.g Adrenal cell in kidney
- Pancreatic tissue in stomach/intestine

Question 4

name the congenital tumours?

Answer 4

-naevi (moles)
- vascular lesions: tumours of blood vessles, occasionally can become malignant

Question 5

name the tumour that arises from germ cell layers?

Answer 5

TERATOMA
-Tumour/mass forming lesion composed of cellular proliferation derived from 3 primitive
germ cell layers: endoderm, ectoderm and mesoderm
-MIDLINE tumours
- Mediastinal or sacrococcygeal
-10% are malignant
-GONADAL: testes / ovary
- Can be benign or malignant

Question 6

outline the sacrococcygeal teratoma morphological classification types

Answer 6

1. entirely extra fatal, with/out a small presacral component
2. extra fatal with intrapelvic extention
3. extra fetal with extension thru the pelvis into abdomen
4. entirely intra fetal without any external component

Question 7

what is neuroblastoma?

Answer 7

-PNS/adrenal
-Tumour of adrenal medulla or sympathetic nervous system/sympathetic
ganglia
-Rare in CNS
- Abdominal swelling
- Metastasis: liver, bone, deposits ion abdomen or peritoneum
-Tumour may secrete catecholamines
- Histology: small, round, blue cells
-Primitive/embryonal cells with rosettes
-Fibril and ganglion differentiation

Question 8

what is nephroblastoma/ wilm’s tumour?

Answer 8

• kidney
  -Malignant tumour arising from primitive blastema of embryonic kidney
  -Familial/Genetic: abnormal deletion in short arm of chromosome 11 (11p13)
  and loss of tumour suppressor gene WT-1
• Histology: small, primitive dark cells with differentiation into tubules and primitive
  glomerular structure
  -Blastemal cells form primitive mesenchymal stroma
  -SPREAD: lymph nodes
  -Metastasis: lung, liver, brain
  -Excellent response to combination of surgery, chemoRx and DXT

Question 9

what is retinoblastoma?

Answer 9

• eye
  -Tumour of primitive retinal cells
  -Autosomal dominant inheritance: 40% cases
  -Transmission of defective allele of tumour suppressor RB gene (13q14)
• Recipient of defective gene undergoes somatic mutation of other allele to activate
  tumour development
• Sporadic: mutations of both alleles
• Familial: may be bilateral and multifocal
  -Clinical: Leukocoria (white pupillary reflex)
  Blindness
  Mass behind eye
  SPREAD: Intraocular
  Extraocular: infiltrates optic nerve and brain
  Periorbital lymph nodes
  Treatment: enucleation and DXT
  Cure rate 90%

Question 10

what is medulloblastoma?

Answer 10

• CNS/ cerebellum
  -Tumour arises from external granular layer of cerebellum
• Midline
• Projects as mass into 4th ventricle
• Blocks flow of CSF and causes raised intracranial pressure with hydrocephalus
• SPREAD: via CSF and CNS dissemination
• Highly aggressive
  -OTHER CNS TUMOURS: astroblastoma, ependymoma (glial neoplasms)

Question 11

what is hepatoblastoma?

Answer 11

• liver
  -Very rare developmental tumour of liver
  -Arises from embryonic hepatic blastema

Question 12

what is rhabdomyosarcoma?

Answer 12

• soft tissue
  -Tumours of embryonic mesenchymal tissue
• Connective tissue, skeletal muscle, adipose tissue, bone
  -RHABDOMYOSARCOMA
• Embryonic skeletal muscle differentiation
• Sites: genital/vagina
  head & neck, orbit, nasopharynx
  bladder
  -OSTEOSARCOMA
  -Distal femur/tibia (knee)

Question 13

what is haematolymphoid malignancy?

Answer 13

-LEUKEMIA
-Acute leukemia
- LYMPHOMA
-Lymphoblastic lymphoma
- Burkitt lymphoma (jaw/orbit)