Questions volume 2 (oncology, few questions in previous volume) Flashcards
Describe which way each of the following labs goes in tumour lysis syndrome (up/down) uric acid potassium phosphate calcium
uric acid increases ->hyperuricemia
potassium increases ->hyperkalemia
phosphate increases ->hyperphosphatemia
secondary hypocalcemia
What is the mechanism of renal failure in tumour lysis syndrome
secondary to uric acid and calcium phosphate crystals in the microvasculature of the kidneys
this can worsen hyperkalemia, lead to fatal arrythmias
All but which of the following is a method to prevent tumour lysis syndrome
a) allopurinol
b) aggressive hydration (2x maintenance)
c) alkalization f the urine for pH>7.5
d) monitoring of electrolytes
c) false - do want to do alkalination to increase the excretion of uric acid, want to monitor the urine pH with target of 7.0-7.5
if 7.5 can lead to calcium phosphate crystal formation
treatment: when abnormalities of metabolics occurs, treat ASAP, if renal failure occurs, need to do dialysis
Which patients are most at risk of complications from leukocytosis?
a) Burkitt’s lymphoma
b) ALL
c) AML
c) patients most at risk of complications from hyperleuocytosis are those with AML
those with ALL and other hematologic malignancies typically do not experience complications unless WBC is greater than 200000
Please list the complications of hyperleukocytosis
Definition: WBC >100000
3 organ systems primarily affected:
1. pulmonary: pulmonary leukostasis and secondary pulmonary hemorrhage
2. CNS: leukostasis in cerebral vasculature, hemorrhagic stroke (more common) ischemic stroke (rare)
3. renal: leukostasis in microvasculature ->renal failure
4. other: leukostasis in small vessels->can lead to priapism, dactylics, GI bleed, pericardial tamponade
4. increased risk of TLS
Which type of stroke is more common secondary to hyperleukocytosis?
a) hemorrhagic
b) ischemic stroke
a) hemorrhagic stroke is more common, ischemic stroke (rare) –>seems counterintuitive
from leukostasis in cerebral vasculature
A patient with AML arrives and has a WBC count of 125. What are your management strategies
Prevent TLS: aggressive hydration, alkalinzation, allopurinol
Prevent hemorrhage ->keep platelets >20
Avoid RBC transfusions ->they can increase viscosity, if needed, consider exchange
If symptoms of leukostasis are present -consider leukapheresis to quickly decrease WBC (temporizing measures)->definitive treatment ->start chemo
True or false - a patient with cancer is complaining of back pain. The neurological exam is normal. Can you rule out cord compression clinically?
No->absence of neurologic symptoms does not rule out cord compression, MRI is the radiographic study of choice
spine X rays are abnormal in <50% of patients with spinal cord compression, but can be a good first step while organizing MRIw (should give dex first if cord syfunction says Oski, if cord compression suspected but no neuro symptoms, lower dex dose and MRI in 24 hours)
progressive neuro symptoms will happen with undiagnosed cord compression
A patient is found to have a mediastinal mass. Please name 7 common causes
- Hodgkin disease
- NOn-Hodgkin lymphoma
- Germ cell tumour
- Neuroblastoma
- Teratoma
- Acute lymphoblastic leukaemia (most commonly T cell, this is why we should always do a CXR in patients with leukaemia)
- Sarcoma
What are two interventions that are contraindicated in medastinal mass patients?
- sedation and anxiolytics
2. place the patient upright
Name two results of anterior mediastinal masses
- compression of the trachea
- compression/obstruction of the SVC ->results in SVC syndrome (characterized by
**Oski says steroids or chemo may be necessary to prevent mortablity/morbidity despite lessening the chance of tissue diagnosis
name 3 risk factors for ALL
- Down syndrome
- Ataxia telangiectasia
- prior exposure to radiation
however in most cases, no predisposing condition exists
Which is the most common childhood cancer
ALL - 1/3 of all childhood cancer
approximately 80-85% of all childhood acute leukaemia is ALL
5000 cases in US each year
arisses in lymphoid cell lineage - can be either B cell or T cell derived
When is the peak age of diagnosis with ALL
age 2-3 (baby nelson says 2-5 year old)
How can you distinguish between infectious mono and ALL?
both can present with HSM, lymphadenopathy, and mild cytopenias
on peripheral smear ->atypical lymphocytes (in mono) vs. leukemic blasts (ALL)** although can be hard to distinguish ; and sometimes in automated readings will say atypical on the initial reading
in general-do P/E, blood smear and bone marrow to diagnose
What is the difference between aplastic anemia and cancer?
aplastic anemia should not have a increased blast count
other malignancies can metastasize to the BM
What are some other childhood illnesses than can be on the differential for ALL?
- JIA - can present with fever, pallor, joint pain, HSM->do BM before steroids
- ITP common in childhood ->ONLY platelets should be affected
- mono (se above)
- aplastic anemia
- other malignancies with mets to the BM - Neuroblastoma, sarcomas, retinoblastoma
All but which of the following is a sign/symptom associated with ALL?
a) testicular atrophy
b) gingival hypertrophy
c) leukemia cutis
d) renal insufficiency
a) in fact testicular enlargement is associated
gingival hypertrophy and leukoemia cutis - most common in infants
other manifestations: BM cytopenias, pain secondary to marrow crowding, HSM, Anterior mediastinal mass, increased LN
Where do chloromas most commonly occur?
in the orbits -results in proptosis, these are tumour of leukaemia cells
Why are boys treated 1 year longer than girls for ALL?
to minimize risk of testicular relapse
Which patients with ALL get intrathecal chemo?
all of them, to treat or prevent CNS involvement
What is the event free survival in ALL
85-90%
Which patients are deemed high risk ALL?
Baby Nelson:
for ALL - 4 prognostic groups based on age, initial WBC count, genetic characteristics and response o induction therapy
Low Risk Patients:
- Age 1-9 year old
- Initial WBC 10 year old
- initial WBC >50 at diagnosis
- CNS or testicular disease at diagnosis
- unfavorable cytogenetics - ie T4;11
Very High Risk Patients:
- hypodiploid DNA index
- t 9;22 translocation
- fail remission after 4 weeks of therapy
Everybody else is standard risk!!
Other factors which can influence: immunophenotype, minimal residual disease, and early response to therapy
Which percentage of childhood leukaemia is AML?
15-20% , equal in male and female
AML is high in neonatal period then drops and stabilizes into teens, then stable into adulthood