What is leukemia?
- Malignancy of hematopoietic cells
- Starts in BONE MARROW, can spread to blood, nodes
- Myeloid or lymphoid
- Acute or chronic
What is lymphoma?
- Malignancy of hematopoietic cells
- Starts in LYMPH NODES, can spread to blood, marrow
- LYMPHOID only
- Hodgkin or non-Hodgkin
What are the three main hematologic malignancies and what are their subclasses?
Leukemias (acute and chronic)
Lymphomas (Hodgkin and Non-hodgkin)
Plasma cell disorders (multiple myeloma)
What are the two different types of myeloid leukemia?
- Acute myeloid leukemia
- Chronic myeloid leukemia
What are the five different types of lymphoid leukemia?
- Acute lymphoblastic leukemia
- Chronic lymphocytic leukemia
- Hodgkin lymphoma
- Non-hodgkin lymphoma
- Multiple Myeloma
How is a malignant hematopathology diagnosis made?
- Clinical setting (symptoms)
- Morphology (bone marrow biopsy/aspirate)
- Immunophenotyping
- Molecular studies
- Cytogenetics
What is involved with a bone marrow biopsy?
- If it’s suspected to be malignant, they’ll get a bone marrow biopsy
- Often pathologists get best sample
- Aim for superior iliac crest on the lower back - find it by palpation
- Jamshidi needle used - it’s a hollow tube that you get the marrow stuck in, you twist the needle a little bit and gently pull it out - you’ll get a toothpick thick, inch long piece of bone
What do you see when you get a bone marrow biopsy?
- Cellularity!!
- You get a good overview of bone composition
- First, look at its cellularity
- Then, look for large collection of odd cells
- As you age, cellularity drops 10% each year (starting in 30s) -In older agent shouldn’t be cellular at all (all filled with fat!)
What do you see in a normal bone marrow biopsy?
-Many cells with some globs of fat, very pink staining
What happens in bone marrow aspiration?
A needle and syringe is used to extract marrow. It will look like thick blood, but it’s bone marrow aspirate
What does normal bone marrow aspirate look like?
- Pink, small very cellular
- Lots of red cells
- Smear it out from one end to the other
What do acute leukemias look like in bone marrow aspirate?
- Many, much darker clumped together cells
- Look like very young cells
What do chronic leukemias look like in bone aspirate?
-Come on more slowly, tend to have more mature cells (more banded/lobed cells)!
What might you see and diagnose in the bone marrow aspirate or blood smear of hodgkin lymphoma?
- Reed Sternberg cell
- Looks like two fried eggs inside one cell (almost like owl eyes
What are the two main stains used to look at these bone marrow cells?
Regular stain - Wright-Giemsa
Cytochemical stain - Non-specific esterase
What are you doing in flow cytometry?
Looking at lymphocytes (WBCs) and sorting them by their cell surface markers (ex: CD3 & CD8)
What are you doing in cytogenetics?
- Looking at DNA in cells
- You take a photo during metaphase & then line up the chromosomes and look at them
- Anything missing? Abnormalities?
- Ex: translocation between chromo 9 and 22 called the Philadelphia - in chronic myeloid leukemia
How else can you look at hematopatholigical malignancies (genetically)?
DO PCR
- Take DNA of cells, put in tube and add primers that flank the sequence you’re looking for
- Then the strands are “cut and pasted” many many times - the you get a pure sample of the section of DNA and can run it on a gel
- You can start with a sample of a very small amount
