Malignant tumours of childhood
Why childhood cancers differ from adult ones (embryonal origin, few mutations, inherited RB1, WT1 and TP53 faults) and how leukaemia, brain tumours, neuroblastoma, Wilms tumour, retinoblastoma and other childhood tumours arise and spread.
By the end, you can
- Explain why childhood cancers differ from adult cancers in origin, genetics and type.
- Explain the two-hit model using retinoblastoma, and name the main inherited predisposition syndromes.
- Relate neuroblastoma, Wilms tumour and the other embryonal tumours to the developing tissue each imitates, with their key gross and microscopic features.
- Explain how childhood tumours spread and what staging, histology and molecular risk features measure.
What it is
A malignant tumour of childhood is a cancer arising in a child or adolescent. Leukaemias, brain tumours and lymphomas are the commonest; most others are embryonal tumours (the "-blastomas"), which imitate immature tissue of a developing organ, or sarcomas of soft tissue and bone. Carcinomas, the main cancers of adults, are rare.
3 types to tell apart
- Blood and lymphoid
- Leukaemias, mostly acute lymphoblastic leukaemia, and lymphomas (Burkitt and lymphoblastic in children, Hodgkin in adolescents).
- Embryonal tumours
- Neuroblastoma, Wilms tumour, retinoblastoma, hepatoblastoma and medulloblastoma: primitive small round blue cells imitating a developing tissue.
- Sarcomas
- Rhabdomyosarcoma in younger children; osteosarcoma and Ewing sarcoma of bone, peaking in adolescence.
US spelling: tumours → tumors, tumour → tumor, leukaemias → leukemias.
Normal function
Precursor cells that should mature and stop
Organs form from precursor cells that divide fast and then mature. In the developing kidney, caps each branch of the collecting system and condenses into a , an and finally a . Similar precursors build the retina, the sympathetic nerves and adrenal medulla (neuroblasts from the neural crest), the liver, skeletal muscle and the cerebellum.
Each population is meant to differentiate and stop: nephron formation ends at about 34 to 36 weeks of gestation, and retinal precursors stop dividing in early childhood. Blood precursors keep dividing for life, and B-lymphocyte production is especially intense in early childhood.
Small nests of precursors sometimes persist: nephrogenic rests in the kidney and tiny neuroblastic nodules in the infant adrenal. Most mature or regress, but they are fertile ground for a tumour.
Underlying change · Step 1 of 5
Why childhood cancers differ, and which are commonest
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Inherited predisposition: retinoblastoma and the two-hit model
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Neuroblastoma: neural crest cells that fail to mature
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Wilms tumour and the other solid tumours
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
How they spread, and what staging and risk features measure
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .