Clinical interpretation of lab exams

Question 1

definition: anisocytosis

Answer 1

RBC size

Question 2

definition: poikilocytosis

Answer 2

RBC morphology

Question 3

normal volume of RBC

Answer 3

80-100 fL

Question 4

on the basis of MCV RBCs can be divided into what categories?

Answer 4

1. microcytic
2. macrocytic
3. normocytic

Question 5

on the basis of etiology RBCs can be divided into what categories?

Answer 5

1. blood loss
2. impaired production
3. increased destruction

Question 6

reticulocyte counts are used to assess what?

Answer 6

erythropoietic activity

Question 7

what is the ESR used for?

Answer 7

if disease is active or not (underlying organic disease)

Question 8

the initial reticulocyte % must be corrected for what factor?

Answer 8

degree of anemia

Question 9

what is the formula for corrected reticulocyte count?

Answer 9

(patient Hct/45) x reticulocyte count

Question 10

what is the normal corrected reticulocyte count value?

Answer 10

3%

Question 11

what are the four main causes of microcytic anemia?

Answer 11

1. iron deficiency (most common)
2. anemia of chronic disease (renal failure)
3. thalassemia
4. sideroblastic anemia (least common)

Question 12

what are the lab tests for microcytic anemia?

Answer 12

1. serum iron
2. serum TIBC
3. % saturation (serum Fe/TIBC)x100
4. serum ferritin

Question 13

what is the single best test for iron storage?

Answer 13

serum ferritin

Question 14

what is the gold standard for diagnosing B thalassemia?

Answer 14

Hb electrophoresis

Question 15

how will serum ferritin look for IDA?

Answer 15

low

Question 16

how will serum ferritin look for ACD?

Answer 16

normal or increased

Question 17

how is blood treated for a direct Coomb’s test?

Answer 17

patient RBCs are pre-treated with antibody

Question 18

lymphoma

Answer 18

lymphoid neoplasms arising as discrete mass

Question 19

leukemia

Answer 19

lymphoid neoplasms with involvement of blood and bone marrow

Question 20

what is the only way to determine if a WBC is coming fro T cell or B cell lineage?

Answer 20

immunophenotyping (IHC, flow cytometry)

Question 21

what is the immunophenotyping marker for B cells?

Answer 21

CD20

Question 22

what is the immunophenotyping marker for T cells?

Answer 22

CD3

Question 23

what is the major blood cancer for patients younger than 10 years of age?

Answer 23

acute leukemia

Question 24

what is the major blood cancer for patients between 10 and 19 years of age?

Answer 24

lymphoma

Question 25

what are the lymphoma staging criteria?

Answer 25

I. single lymph node region or extralymphatic site
II. two or more LN regions or extralymphatic site on same side of diaphragm
III. LN regions or extralymphatic site on both sides of diaphragm
IV. disseminated or diffuse involvement of one or more extralymphatic sites

A - asymptomatic
B - fever, night sweats, or more than 10 lb weight loss