Diseases of WBCs, LNs, Spleen, and Thymus Flashcards
What are the three categories of myeloid neoplasms?
acute myeloid leukemia’s, chronic myeloproliferative disorders, myelodysplastic syndromes.
What are histiocytoses?
uncommon proliferative lesions of macrophages and dendritic cells.
What are some predisposing genetic factors for developing acute leukemias?
down syndrome, type 1 NF, Faconi anemia, bloom syndrome, ataxia telangiectasia.
HTLV-1 is associated in what cancer?
adult T cell leukemia/ lymphoma.
How can reactive and malignant lymphocytosis be differentiated?
Based on clonality: monoclonal is malignant and polyclonal is reacitve.
What is the most common childhood cancer?
Acute Lymphoblastic Leukemia/ lymphoma
Children <15
What is the most common type of ALL?
B-ALL makes up 85%
Ethnicity of ALL?
white-3x more likely.
hispanics have highest risk
Peak age of B-ALL?
3
Peak age of T-ALL?
15
- predominately adolescent males
70% of T-ALLs have what genetic mutation?
NOTCH-1
What translocation is associated with B-ALL?
balanced t(12;21)
*other genes include PAX6,E2A,EBF
What is the morphology of the marrow in leukemic presentations?
Hyper cellular and packed with lymphoblasts.
What are the morphological features of a peripheral smear in a patient with ALL?
Punched out nuclei, blasts appear larger, chromatin is delicate and finely stippled.
What are the differentiating features of myeloblasts compared to lymphoblasts?
Lymphoblasts have more condensed chromatin, less conspicuous nucleoli, and smaller amounts of cytoplasm that usually lacks granules.
What stain can be used to identify myeloblasts?
myeloperoxidase (MPO)
Lymphoblasts are characterized by positive nuclear staining for what?
TdT.
What CDs are expressed in B-ALLs?
CD-10, 19, 20
What CDs are expressed in T-ALLs?
CD-1,2,5,7
** not CD-10!
What are the common symptoms associated with ALL?
Anemia (fatigue), thrombocytopenia (bleeding), neutropenia (infection)
What is the prognosis of ALL in children?
aggressive chemotherapy–> 95% success rate
What factors favor a good prognosis in ALL?
t(12;21), age 2-10, hyperdiploidly, trisomy of chromosomes 4,7,10.
What translocation in ALL yields a poor prognosis?
t(9;22)
What fusion gene is created in the t(9;22) form of ALL?
BCR-ABL tyrosine kinase
- Philadelphia +