Acute Lymphoblastic Leukemia/Lymphomas & T/NK-cell Non-Hodgkin Lymphoma Flashcards
What are lymphoblasts? They express what cytogenic markers?
lymphocyte precursors - few or none of the morphologic or immunologic features of mature lymphocytes
small to medium size with round, oval nuclei & fine chromatin - few/inconspicuous nucleoli & frequent mitotic figures, scant cytoplasm, PAS-positive cytoplasmic granules
most express CD34, CD19, CD10, TdT, HLA-DR
What is the difference between lymphoblastic leukemeia & lymphoblastic lymphoma?
-
leukemia
- significant blood/bone marrow involvement (most are B-cell)
-
lymphoma
- mass lesion with no/minimal blood/bone marrow involvement (most are T-cell)
If a patient presents with tissue mass & blood/bone marrow involvement, what blast count qualifies the condition as Acute Lymphoblastic Leukemia?
25%
What is the most common childhood malignancy?
B-ALL (leukemia)
>75% cases are seen in children under 6 yrs
What is the difference in age demographics most commonly affected by B-ALL and B-LBL?
B-ALL >75% under 6 yrs
B-LBL teenagers & young adults
What is the clinical picture of patients with B-ALL/LBL?
- common extramedullary involvement
- lymphadenopathy, hepato/splenomegaly
- bone pain
- fever, weight loss, night sweats
Is B-ALL or T/NK-ALL more common?
85% of all ALL are B-cell
Is B-LBL or T/NK-LBL more common?
most are T/NK-LBL
What CBC laboratory findings would you expect to see in a patient with B-ALL?
variable WBC count
anemia & thrombocytopenia
rarely - reactive eosinophilia
What are the environmental risk factors associated with B-ALL/LBL?
radiation
toxins
previous chemotherapy
What are the genetic factors associated with B-ALL/LBL?
genetic abnormalities
second “hit” may be required for development overt leukemia
clonal IgH (heavy chain) gene
Down Syndrome
familial predisposition
What would you expect to see in a peripheral blood smear in a patient with B-ALL/LBL?
-
leukoerythroblastosis
- granulocyte precursors, nucleated RBC & lymphoblasts
- L1 blasts- smaller, scant & condensed chromatin (circled) - mimic mature cells
- L2 blasts- larger, moderate cytoplasm & “smudgy chromatin, prominent nucleoli (blue curved arrow)
- blasts are negative for myeloperoxidase & other myeloid markers
- cell morphology of non-neoplastic cells is normal - NO dysplastic myeloid cells
*won’t have to recognize difference between L1 & L2
What would you expect to see from a bone marrow aspirate in a patient with B-ALL/LBL?
hypercellular w/ high percentage lymphoblasts & numerous mitoses- think monotonous population
rarely, regions of necrosis (areas where they outgrew blood supply- will look more pink than blue)
What condition is indicative of the provided peripheral blood smear & bone marrow aspirate?
B-ALL/LBL
What would you expect to see in a lymph node biopsy from a patient with B-ALL/LBL?
partial to complete effacement of architecture
diffuse infiltrative pattern with no nodularity
many mitoses
similar to blastoid mantle cell lymphoma & Burkitt lymphoma
What cytogenic markers are seen in patients with B-ALL/LBL?
CD19 (& other pan-B cell markers)
CD34 and TdT (markers of immaturity)
What variables are good prognostic indicators in B-ALL/LBL?
1-10 yrs
female
WBC < 50,000
absence CNS disease
common inmmunophenotype
hyperdiploidy > 50 chromosomes
(>95% remission rate & about 80% cured)
What variables are poor prognostic indicators in B-ALL/LBL?
<1 yr and >10 yrs
male
WBC > 50,000
presence CNS disease
absence CD10
hypodiploidy < 45 chromosomes
T-ALL/LBL is most common in what demographic of people?
adolescent males
What clinical picture would you expect to see in a patient with T-ALL?
- adolescent male
- bone marrow involvement (by definition)
- mediastinal involvement is common (rapidly growing mass)
- lymphadenopathy & hepatosplenomegaly
- CNS involvement is more common than in T-LBL
What clinical picture would you expect to see in a patient with T-LBL?
- adolescent male
- rapidly growing anterior mediastinal/thymic mass
- pleural/pericardial effusion
- bone marrow (<25% lymphoblasts)
- may have involvement of lymph nodes & extranodal sites
What values would you expect to see from a CBC and peripheral blood smear from a patient with T-ALL/LBL?
marked peripheral blood leukocytosis with high blast count
blasts are usually indistinguishable from B-ALL
What cytogenic markers would you expect to see in a patient with T-ALL/LBL?
TdT, CD34, CD2, CD5, CD7, +/-CD10
What is the difference in prognosis for in comparison to their B-cell counterparts:
Childhood T-ALL
Adult T-ALL
Pediatric T-LBL
Adult T-LBL
-
Childhood T-ALL
- higher risk than B-ALL/LBL
-
Adult T-ALL
- better prognosis than B-ALL
-
Pediatric T-LBL
- worse prognosis than with B-LBL
-
Adult T-LBL
- varies with age, worse if >40 yr
Are mature T-cell neoplasms more or less common than mature B-cell neoplasms?
much less common
Are mature T-cell neoplasms more or less common than mature B-cell neoplasms?
much less common than B-cell neoplasms
Mature T-cell neoplasm typically have what type of growth pattern?
diffuse
usually with mixed inflammatory cell background
Why are mature T-cell neoplasms difficult to diagnose by flow cytometry?
more likely to be detected by T-cell antigens lost than expressed
As a group, do mature T-cell lymphomas have a better or worse prognosis than most B-cell lymphomas?
T-cells generally have a significantly worse prognosis
What is Mycosis Fungoides?
malignancy of CD4(+), CD8(-) T lymphocytes with loss of CD7 or another T-cell marker