Pediatric Oncology

Question 1

Initial Testing based on Presentation

Answer 1

• CXR - mediastinal mass
• US/CT of abdomen - abdominal tumor
• Brain CT
• CBC - pancytopenia or lymphocytosis
• peripheral smear - immature forms (blasts)

Question 2

MC Childhood Malignancies

Answer 2

• ALL / AML (25%)*
• CNS tumors (17%)
• Neuroblastoma (7%)
• Wilms
• Non-Hodgkin lymphoma
• Hodgkins
• Rhabdomyosarcoma
• Osteosarcoma
• Ewing

Question 3

Causes/Types of Leukemia

Answer 3

• causes
  
  • unknown
  • predisposed- Downs, Wiskott Aldrich syndrome, neurofibromatosis
  • sibling w/ leukemia
  • radiation/chemotherapy
• types
  
  • Acute Lymphoblastic (ALL) - 75%
  • Acute Myelogenous (AML) - 15%
  • Chronic Myelogenous (CML)

Question 4

Classification of ALL

Answer 4

based on morphology of cancerous cells

• B cell lineage
• T cell lineage
• Burkitts lymphoma
• MC in boys than girls
• peaks at age 2-5

Question 5

Classification of AML

Answer 5

based cell types involved in proliferation

• AML without maturation
• AML with maturation
• myelomonocytic
• monoblastic and monocytic
• erythroid
• megakaryoblastic
• basophylic
• panmyelosis w/ myelofibrosis

Question 6

Presentation of Leukemia*

Answer 6

• fever
• pallor
• bruising or petechiae
• lethargy or malaise
• anorexia
• bone or joint pain

Question 7

Physical Findings in Leukemia

Answer 7

• weight loss
• ill appearance, fatigue
• cough (secondary to mediastinal involvement)
• pallor (secondary to anemia)
• lymphadenopathy
• abdominal mass, splenomegaly
• testicular mass
• various soft tissue tumors in AML

Question 8

Evaluation of Leukemia

Answer 8

• immature blasts on peripheral smear
• urgent consultation
• bone marrow aspiration (dx confirmation)
• LP to determine CNS spread
• cytogenetic analysis to begin tx planning

Question 9

ALL Chemo

Answer 9

• 3-4 agents
• IV or intrathecally for CNS
• 2-3 years

Question 10

AML Chemo

Answer 10

• intensive myelosuppressive therapy
• may need stem cell transplant (HLA matched sibling)

Question 11

ALL Prognosis

Answer 11

• overall cure rate 80%
• low, standard, high, very high
• based on age, initial WBC count, genetics, response to induction therapy
• relapse during tx poor prognostic sign
• relapse can be bone marrow, CNS, testes, other site

Question 12

AML Prognosis

Answer 12

• 50% cure rate
• improved with HLA matched stem cell transplantation from sibling

Question 13

Hodgkin’s Disease

S/s, Dx, Tx

Answer 13

• bimodal distribution
  
  • adolescent/young adult and >50
• S/s
  
  • firm, painless lymph node in 1-2 areas
    
    • usually supraclavicular, cervical
    • mediastinal w/ cough and SOB
    • abdominal w/ pain
  • suspected w/ EBV infection
• Dx
  
  • CBC, ESR, electolytes, Ca+, phosphorous, LDH, uric acid, CXR
  • biopsy of affected tissue
  • Reed Sternberg cells*
• Tx
  
  • combo chemo and irradiation
  • 90% overall 5 year survival

Question 14

Non-Hodgkin Lymphoma

characteristics / subtypes

Answer 14

• subtypes
  
  • lymphoblastic lymphoma
  • small noncleaved cell lymphoma
  • large cell lymphoma
• characteristics
  
  • suspected assoc. w/ EBV - focal lymph nodes
  • typically systemic - bulky extramedullary disease

Question 15

CNS Tumor Presentation

Answer 15

2nd MC tumor in children

• HA (usually later)
• altered mental status
• ataxia
• NAV, weight loss
• gait disturbance
• focal seizures
• visual changes
• speech deficits
• focal sensory abnormalities

Question 16

CNS Tumors

Characteristics, S/s, Dx, Tx

Answer 16

• bimodal peak: age <10 and >70
• S/s
  
  • papilledema
  • diplopia (6th n. compression)
  • Parinaud syndrome - impaired upward gaze (pineal tumors)
  • homonymous hemianopia (occipital tumors)
  • anosmia (frontal lobe tumors)
  • brainstem and cerebellar tumors- CN palsies, ataxia, sensory deficits, nystagmus, pyrimidal signs
• Dx
  
  • must ID secondary tumors
  • MRI is study of choice (except subarachnoid space)
• Tx
  
  • Dexamethasone - emerg. swelling
  • surgical excision/debulking
  • radiation/chemo

Question 17

Neuroblastoma

Characteristics, S/s, Dx, Tx

(derived from neural crest cells that form medulla & SNS)

Answer 17

• MC intraabdominal malignancy of infancy
• MC before age 1, rare after 10
• S/s
  
  • abdominal mass crosses midline & bone pain
  • chest/neck mass w/ Horner syndrome, spinal cord compression
  • 50% w/ mets at time of dx
• Dx
  
  • x-ray, US ab, bone scan, CT/MRI
  • CBC, LFT, ESR catecholamine by-products (HVA, VMA)
  • biopsy of mass essential
• Tx
  
  • surgical excision
  • excision of bulk + chemo/radiation

Question 18

Wilms Tumor

Characteristics, S/s, Dx, Tx

Answer 18

• nephroblastoma (primitive kidney cells)
• MC intraabdominal malignancy of childhood (avg age 3)
• S/s
  
  • abdominal mass, pain, hematuria, hypertension
• Dx
  
  • ab US, CT/MRI
• Tx
  
  • nephrectomy with chemo
  • preserve some tissue if bilateral

Question 19

Retinoblastoma

Characteristics, S/s, Dx, Tx

Answer 19

• avg age 18mo, rare after 5
• RB1 gene mutation - other malignancies
• S/s
  
  • leukocoria (white pupillary reflex)
• Tx
  
  • radiation, radioactive isotopes, chemo, surgical enucleation if no vision preserved

Question 20

Sarcomas (solid tissue tumors)

Types, Dx, Tx

Answer 20

• Types
  
  • Rhabdomyosarcoma (MC soft tissue kids)
    
    • 2-6: head/neck, genitourinary tumor
    • adolesc: extremities, trunk, male GU
  • Osteosarcoma
    
    • distal femur, proximal tibia/humorus
    • epi/metaphysis of max growth bone
  • Ewing sarcoma
    
    • any bone (femur/pelvis MC)
• Dx
  
  • biopsy: small round blue cell tumors
  • Ewing- specific chromosomal transloc.
  • check for mets- bone scan, CT, marrow
• Tx
  
  • depends on staging
  • surgery, chemo, radiation