Promyelocytic blast
- Size : Around 20µm
- N/C ratio= Low
- Cytoplasm
- Extension : Abundant
- Basophilia : Slightly intense
- Number of granules : Numerous
- Color of granules : Red = azurophils
- Membrane : Regular
- Nucleus
- Situation : Eccentric
- Chromatin : Fine
- Nucleoli : Absent
- Membrane : Regular
- Normal values : Absent in the blood and bone marrow
- Description / Pathology :
Large size cell, oval, with nucleus often lobed as butterfly wings, fine chromatine, very granular basophilic cytoplasm (many azurophilic granules) with Auer rods in bundles (pathognomonic).
Acute promyelocytic leukemia (FAB classification AML3/ AML classically with t (15; 17) WHO classification.