Normal White Blood Cell morphology

Question 1

Compare a Myeloblast to a Promyelocyte

Answer 1

Myeloblast: 12 to 20 um, deep basophilic cytoplasm, nucleus has fine chromatin and 1-2 distinct nucleoli, no granules or golgi.
Promyelocyte: slightly larger at 15 to 25 um; primary azurophilic (dark purple) granules in basophilic cytoplasm; pale golgi area next to nucleus

Question 2

Describe a Monoblast: how does it differ from a myeloblast?

Answer 2

It is 15 to 25 um (larger than a myeloblast at 15 to 20), has a larger amount of cytoplasm relative to a myeloblast, and light blue-gray cytoplasm often with vacuoles; both have nucleoli but myelo’s are distinct

Question 3

How does a promonocyte appear differently from a mature monocyte?

Answer 3

the nucleus has a folded-tissue paper appearance and is still round, whereas it is more convoluted and has more open lacy chromatin in a mature monocyte

Question 4

How would you differentiate a large lymphocyte from a similarly sized, rounder-nucleated monocyte?

Answer 4

Lymphocytes have more diffusely clumped chromatin and clearer lighter blue cytoplasm, whereas the monocyte should have more open chromatin (more lighter spaces) and a mottled blue-gray cytoplasm possible with vacuoles

Question 5

Give 3 attributes of a promyelocyte

Answer 5

1. large round to oval nucleus with usually a nucleoli visible
2. largest of myelocytic series, 15 to 25 um
3. Appearance of azurophilic granules which are dark purple, but NO SIGN of pink secondary granules

Question 6

3 attributes of a myelocyte

Answer 6

1. appearance of pink-salmon-lilac secondary granules is the hallmark! (or the red or deep blue of eosinophils and basophils’ 2ndary granules)
2. chromatin is moderately to coarsely clumped (was finer in promyelo)
3. NO NUCLEOLI

Question 7

3 attributes of metamyelocyte

Answer 7

1. nucleus indented
2. cytoplasm pinkish blue/ few if any primary granules, only secondary
3. NO NUCLEOLI

Question 8

3 attributes of a segmented neutrophil

Answer 8

1. 2 to 5 lobes connected by thin chromatin threads
2. may be small nuclear appendages on the lobes
3. abundant cytoplasm with many secondary grans

Question 9

3 attributes of a monocyte that help you id

Answer 9

1. gray-blue “mottled” cytoplasm (not clear, but no granules)
2. convoluted amorphous nucleus with open “lacy” chromatin
3. often have vacuoles and/or “blebs” / pseudopods. and larger than most lymphocytes

Question 10

how is a prolymphocyte different from a lymphocyte?

Answer 10

it is slightly larger (9 to 18 vs 7 to 15 um), greater N:C ratio, and condensed clumped blue-purple chromatin with a possible nucleolus vs homogenous coarse chromatin in a mature lymph