Study group discussion: Acute myelogenous leukemia

A 67-year-old man presents to his physician with a 10-day history of fatigue, bleeding gums, cellulitis, and a recent weight loss of 9 kg (20 lb). On physical examination, the patient is pale but has no evidence of lymphadenopathy or hepatosplenomegaly. Results of a complete blood count are as follows: WBC count: 18,300/mm3 (75% blastocytes, 20% lymphocytes) Hemoglobin: 9.1 g/dL Hematocrit: 29% Platelet count: 98,000/mm3 diagnosis?

He has acute myelogenous leukemia. It's acute because of the blasts.

Yes, acute myelogenous leukemia.

What could be find in marrow biopsy?

Lots of cells! Sometimes there could be fibrosis though which would lead to a dry tap.

Can anyone tell why the platelet count is affected? (Conceptual review question)

Isn't it in normal limits? 100k-150k?

Then why did he have bleeding gums?

Megakaryocyte lineage affected.

Yup the excessive growth of myeloid series doesn't not allow growth of megakaryocyte.

It is AML M5.

Isn't the bleeding gums due to thrombocytopenia?

I have seen a patient with type 5 AML in my hospital. They don't have bleeding gums. Rather a swelling of gums due to infiltration of leukemic cells. Gingival infiltration it's called I think.

Chloroma.

What's chloroma?

Infiltration of leukaemic cells in soft tissues.

That happens in ALL too, right? The infiltration of leukaemic cells into tissues?

Yes, I think.

I had seen a picture with a child having a chloroma of the orbit.

I thought the WBC count goes in lakhs in AML.

The count doesn't really help because sometimes the counts are comparable to a normal infection.

Oh.

What do we use for differentiating leukemia from infection?

The LAP.

What are the other causes of leukemoid reaction?

The major causes of leukemoid reactions are severe infections, intoxications, malignancies, severe hemorrhage, or acute hemolysis.
Source: http://www.ncbi.nlm.nih.gov/pubmed/16962944