Introduction to Hematologic Malignancy

During this lecture, we learned how to approach Hematologic Malignancy, with the focus on 5 major diseases: leukemia, lymphoma, myeloproliferative disorder (MPD), myelodysplastic syndrome (MDS) and multiple myeloma. The approach begins with asking three questions:

1. Where did the malignancy arise (bone marrow or lymph node + extranodal tissue)?
2. What type of cell is it (myeloid or lymphoid)?
3. What are the malignant cells doing?

Based on the answers to these questions, we can start to figure out what type of malignancy we might be dealing with.

 
Question 1 – “Where did the malignancy arise?”

If the answer is bone marrow, consider: Leukemia, Myeloproliferative Disorder (MPD), Myelodysplastic Syndrome (MDS) and Multiple Myeloma. If the answer is lymph node or extranodal tissue, think: Lymphoma.

Question 2 – “What type of cell is it?”

If the answer is myeloid cells, consider Acute Myeloid Leukemia (AML), myeloproliferative disorder or Myelodysplastic syndrome. If the malignant cells are lympoid, think: Acute lympoid leukemia, chronic lympoid leukemia, multiple myeloma or lymphoma…

Question 3 – “What are the malignant cells doing?” *Only ask this question if the answer to the first question is “bone marrow.” If the bone marrow malignancy consists of all blasts, it is called “acute”. If the cells are not all blasts, it is called “chronic”.

One of the diagnostic tests for hematolgic malignancies is the bone marrow aspirate, illustrated in the bottom left of the Daily Doodle, and lymph node biopsy.  The background of the Daily Doodle represents a smear from a bone marrow aspiration which contains myeloid blasts with auer rods which are a characteristic of Acute Myeloid Leukemia (AML).

EXAMPLES:

Putting it all together with a few examples from the lecture: If the malignant cells are lymphoid, arise in the bone marrow, and are trapped in the blast stage, it is called: ACUTE LYMPHOID LEUKEMIA.

Example 2: If the malignant cells are myeloid, arise in the marrow, and are
trapped in the blast stage, it is called: ACUTE MYELOID LEUKEMIA.

Example 3: If the malignant cells are mature lymphoid cells, arising in the marrow, we call that: CHRONIC LYMPHOID LEUKEMIA.

If the malignant cells are all plasma cells, it is called MULTIPLE MYELOMA.

If the malignant cells are myeloid and are PROLIFERATING way too much, it is called: MYELOPROLIFERATIVE DISORDER.

If the malignant cells are myeloid and MATURE ABNORMALLY, it is called:
MYELODYSPLASTIC SYNDROME.

REFERENCES:

Dr. Jason Ford, “Introduction to Hematologic Malignancy Lecture Notes” September 30, 2011