Pediatric Tumors

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Pediatric Tumors: General Concepts - Tiny Terrors Intro

  • Differ from adult tumors: embryonal origin (vs. epithelial), better prognosis, often chemo/radiosensitive.

  • Common patterns: often arise from developmental rests; may regress spontaneously (e.g., neuroblastoma).

  • Key Genetic Syndromes & Associated Tumors:

    SyndromeAssociated Tumors
    Beckwith-WiedemannWilms tumor, hepatoblastoma, neuroblastoma
    Li-FraumeniSarcomas, brain tumors, leukemia, adrenocortical Ca
    Neurofibromatosis 1 (NF1)Neurofibromas, optic glioma, pheochromocytoma
    WAGR SyndromeWilms tumor, Aniridia, Genitourinary anomalies, mental Retardation
    Denys-Drash SyndromeWilms tumor, gonadal dysgenesis, nephropathy

⭐ Small round blue cell tumors (e.g., neuroblastoma, Ewing sarcoma, Wilms tumor, rhabdomyosarcoma, lymphoma/leukemia) are a characteristic group in pediatric oncology.

Small round blue cell tumors under microscope

Neuroblastoma - Adrenal Annihilators

  • Origin: Neural crest cells (sympathetic nervous system).
  • Sites: Adrenal medulla (most common), paraspinal ganglia.
  • Age: Median ~2 years; prognosis significantly better if <18 months.
  • Presentation: Abdominal mass (firm, irregular, often crosses midline), opsoclonus-myoclonus syndrome ("dancing eyes, dancing feet"), Horner's syndrome, blueberry muffin rash (skin mets).
  • Investigations: ↑ Urine VMA/HVA; MIBG scan (specific uptake); Bone marrow biopsy (staging).
  • Staging: INSS / INRGSS systems.
  • Prognostic Factors: Age (<18mo favorable), stage (lower better), N-myc amplification (📌 Nasty MYC = poor prognosis), histology (Shimada: favorable/unfavorable).

⭐ Neuroblastoma is known for spontaneous regression, especially in infants <1 year with Stage 4S disease.

Wilms Tumor - Kidney Kidnappers

Sagittal CT showing large Wilms tumor

  • Origin: Metanephric blastema (embryonic kidney cells).
  • Age: Peak 3-4 yrs; 90% diagnosed < 7 yrs. Usually unilateral.
  • Presentation: Asymptomatic abdominal mass (most common; smooth, firm, rarely crosses midline). Hematuria, hypertension (renin ↑), abdominal pain, fever.
  • Associated Syndromes:
    SyndromeKey Features (Gene Defect)
    WAGR📌 Wilms, Aniridia, GU anomalies, Retardation (11p13, WT1 del)
    Denys-DrashGonadal dysgenesis, early nephropathy, Wilms (WT1 mut)
    Beckwith-WiedemannMacroglossia, omphalocele, hemihypertrophy, Wilms (11p15.5, WT2)
  • Histology: Triphasic: blastemal, epithelial (tubules), stromal. Favorable (FH) vs. Anaplastic (unfavorable; nuclear atypia).
  • Staging (NWTS - National Wilms Tumor Study):

⭐ Bilateral Wilms tumor occurs in 5-10% of cases, often has an earlier age of onset, and frequently requires modified treatment protocols including neoadjuvant chemo.

Other Key Pediatric Tumors - Malignant Minis Mix

  • Rhabdomyosarcoma (RMS): Most common pediatric soft tissue sarcoma.
    TypePrognosisCommon Sites
    EmbryonalBetterHead/Neck, GU (e.g., sarcoma botryoides)
    AlveolarWorseExtremities, Trunk
  • Retinoblastoma: RB1 gene. Signs: leukocoria (white reflex), strabismus.

    ⭐ Leukocoria (white pupillary reflex) is a classic sign of Retinoblastoma. Retinoblastoma and Leukocoria Diagram

  • Hepatoblastoma: Most common pediatric liver tumor. Marker: ↑ AFP. Assoc: BWS, FAP.
  • Bone Sarcomas:
    • Osteosarcoma: Metaphysis, sunburst pattern.
    • Ewing Sarcoma: Diaphysis, onion-skin appearance, small round blue cells.

High‑Yield Points - ⚡ Biggest Takeaways

  • Wilms' tumor: Most common pediatric renal mass; linked to WAGR, Denys-Drash, BWS.
  • Neuroblastoma: Top extracranial solid tumor; N-myc (poor prognosis); ↑ VMA/HVA; opsoclonus-myoclonus.
  • Retinoblastoma: Presents with leukocoria (white reflex); RB1 gene mutation.
  • Hepatoblastoma: Main pediatric liver cancer; ↑ AFP; linked to BWS, FAP.
  • Rhabdomyosarcoma: Top pediatric soft tissue sarcoma; common in head/neck, GU tract.
  • Brain tumors: Most common solid tumors; often infratentorial (e.g., medulloblastoma).

Practice Questions: Pediatric Tumors

Test your understanding with these related questions

A 3-year-old boy is found to have spontaneous bursts of non-rhythmic conjugate eye movements in various directions, as well as hypotonia and myoclonus. Physical examination also reveals an abdominal mass. A CT scan shows a mass in the adrenal gland. Which of the following statements is false regarding the patient's condition?

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Flashcards: Pediatric Tumors

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According to modified Bell staging, presence of signs of generalized peritonitis and definitive ascitis is classified as stage _____

TAP TO REVEAL ANSWER

According to modified Bell staging, presence of signs of generalized peritonitis and definitive ascitis is classified as stage _____

IIIA

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