Lesson 03-04

Question 1

Describe spherocytes

Answer 1

Microscopic features:
- smaller than normal RBC
- very round
- no central pallor

Question 2

Describe ovalocytes/elliptocytes

Answer 2

Microscopic features:
- variable in size but longer & narrower than normal RBC
- have central pallor

Question 3

Describe crenated cells / echinocytes

Answer 3

Microscopic features:
- smaller / same size as normal RBC
- have regular blunt projections of red cell membrane

Question 4

Describe schistocytes/acanthocytes/fragmented cells

Answer 4

Microscopic features:
- smaller than normal RBC
- almost no central pallor
- have irregular sharp projections of the red cell membrane

Question 5

Describe teardrop cells

Answer 5

Due to pitting
Microscopic features:
- shaped like a tear drop

Question 6

Describe stomatocytes

Answer 6

Microscopic features:
- about the same size as a normal RBC
- have a slit-like central pallor

Question 7

Describe target cells/codocytes/Mexican hat cells

Answer 7

Microscopic features:
- about the same size as a normal RBC
- adopt a “bullseye” morphology

Question 8

Describe sickle cell

Answer 8

Microscopic features:
- Elongated RBCs with 2 pointed ends
- Show dense haemoglobin, staining red to purple
- No central pallor

Question 9

Describe Howell-Jolly bodies

Answer 9

Microscopic features:
- Smooth, round basophilic cytoplasmic inclusions
- Composed of DNA fragments

Iron stain (-ve)
DNA stain (+ve)

Question 10

Describe basophilic stippling

Answer 10

Microscopic features:
- Very small
- Blue-grey granules distributed throughout the cytoplasm of RBCs
- Can be seen on Wright-Giemsa staining

Question 11

Describe Heinz bodies

Answer 11

Microscopic features:
- Purple-blue inclusions
- Visible only after supravital stain
- Composed of denatured precipitated haemoglobin

Question 12

Describe pappenheimer bodies

Answer 12

Microscopic features:
- Abnormal iron granules found inside RBCs on routine blood stain
- Appear as dense, blue-purple granules within RBCs
- Formed by phagosomes that engulfed excessive iron

iron stain (+ve)

Question 13

Describe Cabot rings

Answer 13

Microscopic features:
- Thin, threadlike, red to violet rings/figure 8 inclusions
- Microtubules that are remnants from a mitotic spindle

Question 14

Describe RBCs infected by protozoan parasites

Answer 14

Microscopic features:
- Multiple parasites present within RBCs
- Round to oval ring-shaped
- Organisms may form a “maltese cross” after division into 4 organisms

Question 15

Describe RBCs infected by malaria parasite

Answer 15

Microscopic features:
- Red nuclear chromatin
- Blue cytoplasm
- Brownish-black malarial pigment