Hi Jordan!
When my doctor wanted to see a differential he always ment a WBC differential from blood. He was interested in the blast cells. During many years I had 0.1 - 0.2% blast cells that is common among MDS patients. They should be 0.
When I had been taking Thalidmide during three years my blast cells i blood was 0.
After my 4th neutropenic fever period (2014-12-24 - 2014-12-30) my blast cells in blood was 2.5% and my doctor explained that my MDS was transforming to AML.
Here is info about WBC differential:
http://www.mdguidelines.com/myeloid-leukemia
As far as I understand MDS patients can have a lot of dysplastic (malshaped blood cells) so looking very often at the morphology of the platelets and the morphology of the red cells is really not so important.
Kind regards
Birgitta-A