Lymphoid Leukemias - Harrington & Atallah Flashcards
Describe the signifiance of clonality in assessing lymphocytoses.
Clonality will reveal if the proess is pathologic; neoplasms will cause a monoclonal expansion, whereas most infections or other benign expansions will exhibit polyclonal characteristics.
Infectious Mononucleosis
Describe the etiology.
What signs and symptoms are seen?
Infectious Mononucleosis
EBV infection (usually occurring in teenagers) causes a lymphocytic expansion and may go dormant in B cells.
Fever, sore throat, LAD, splenomegaly…
What absolute lymphocyte count is considered a lymphocytosis?
What are some benign causes for lymphocytosis?
>4000 per microliter.
Viral infection (CMV, adeno, hepatitis, mononucleosis), pertussis, TB, and “transient stress lymphocytosis”.
How can the clonality of a B cell colony be determined? T/NK cells?
Both can be studied immunophenotypically (presumably with flow cytometry).
Heavy chain (or TCR) gene can be assessed with PCR.
Light chain patterns on B cells can be studied with flow cytometry or IHC.
What is the pathognomonic histological finding in infectious mononucleosis?
What 3 diagnostic criteria are needed?
“Atypical” lymphocytosis.
>50% mononuclear cells in WBC diff, >10% reactive lymphocytes, marked lymphocytic heterogeneity.
What criteria determines an acute leukemia?
What is the difference between a lymphoma and leukemia?
Presence of >20% blasts in peripheral blood or bone marrow.
Lymphomas originate in the tissues (spleen, lymph nodes, MALT/GALT, etc). Leukemias originate in the blood & marrow.
What is the most common ALL?
Who does it predominanttly affect?
B-ALL.
Children.
What can distinguish an AML from an ALL?
Presence of Auer rods in AML, in addition to CD13/14/15/33/117 and MPO presence.
Presence of CD3/19/20 in ALL.
Who do AMLs generally affect?
What are their subclasses, again?
Adults more than children.
AML w/ recurrent cytogenetic abnormalities, MDS-associated changes, therapy-related, and “NOS”
Summarize the prognostic factors of B-ALL. Which are good? Bad?
Good: Age (2-10yrs), hyperdiploidy, t(12;21)
Bad: CSF involvement, high WBC count, marrow involvement following treatment, t(9;22), MLL mutation, hypodiploidy.
Try to recall B-ALL’s typical immunophenotype.
CD34+
CD10+
TDT+
CD19+
CD20-
Who does T-ALL classically affect?
Describe its presentation and outlook.
Try to recall its immunophenotype.
Adolescent males.
Present with mediastinal mass; aggressive.
CD3+, CD4/8+, TDT+.
What are the four steps used in a typical treatment regimen for ALL?
What sites must be treated directly?
Induction, intensification, CNS prophylaxis, maintenance.
The CNS…and testes.
Compare and contrast the outlook of ALL in general in adults and children.
In adults, half die from AML while half enter remission.
Better overall prognosis in children.
