Hematology Case Study 3
Ms. Kate Allison, a 36-year-old female, experienced a recent 35-pound weight loss. Her
tongue was red and fissured. She also complained of chronic fatigue and shortness of
breath upon exertion. Physical examination suggested signs of jaundice and decreased
fibratory sensation of fingers and toes. She was hospitalized with a general diagnosis of
moderate anemia, jaundice, and neurological symptoms. Her admitting CBC
demonstrated the following laboratory results:
WBC:
RBC:
HGB:
HCT:
MCV:
MCH:
MCHC:
RDW:
PLT:

4.5 x109/L
2.50 x 1012/L
10.0g/dL
31 %
124.0 fL
40.5 pg/dL
32.7 gm/dL
21.2
155 x 109/L
Differential:
Lymphocyte %
Monocytes %
Neutrophils %
Eosinophils %
Basophils %
36.0
3.8
59.4
1.0
0.0
NRBCs/100 WBCs: 5
Moderate number of hypersegmented neutrophils
The following abnormal erythrocyte morphology was reported (on a scale of 1-4):
Macrocytes:
2+
Anisocytosis
3+
Poikilocytosis:
2+
Ovalocytes:
1+
Basophilic stippling: 1+
Occasional Howell-Jolly bodies
1.
What is the morphological classification of the patient’s anemia?
Macrocytic
Based on the initial CBC results, further testing was ordered with the following results:
B12:
Folate:
Total bilirubin
*AST:
*ALT:

<50 pg/mL
10.3 ng/mL
2.5 mg/dL
35 U/mL
30 U/mL
(Low)
(Normal)
(High)
(Normal)
(Normal)
*These are liver enzymes that may increase with liver damage.
Examination of a bone marrow aspirate revealed an erythroblastic hyperplasia with
megaloblastic normoblasts.
2.
Based on the information obtained so far, what is the most likely diagnosis?
There is a vitamin B12 deficiency. The patient was admitted with signs of a
moderate hemolytic anemia and neurological symptoms. Her CBC shows that
she has a macrocytic anemia. Her leukocyte and platlet counts are the lower
end of the normal range, indicating a developing pancytopenia. The blood
smear revealed hypersegmented neutrophils, ovalocytes and Howell Jolly
bodies. Her bilirubin values support a diagnosis of hemolysis. On a
differential diagnosis, neurological symptoms typically accompany B12
deficiency rather than a folate deficiency. Based on her serum vitamin B12 and
folate results, she can definitively be diagnosed as having a megaloblastic
anemia due to a vitamin B12 deficiency.
3.
What is the significance of the AST/ALT results?
There is no liver disease. Since the liver enzymes are normal, liver disease is
rules out as a source of jaundice or the macrocytic anemia.
4.
What further testing can be done to obtain a definitive diagnosis?
Testing for antibodies against intrinsic factor, Schilling test, gastric analysis.
A common cause of vitamin B12 deficiency in a patient with no previous
gastrointestinal history is pernicious anemia. The Schilling test can determine
if the deficiency is due to absence of intrinsic factor, or some malabsorption
disorder.
A Schilling test and antibody test were done with the following results:
Schilling Test:
Part I, before intrinsic factor: 1%
Part II, after intrinsic factor: 8%
(Normal is >7.5%)
Intrinsic factor blocking antibodies: Positive to a titer of 1:6400
5.
What is the patient’s definitive diagnosis?
Pernicious anemia. The Schilling test result in Part I showed less than 7% of
the initially radioactively tagged radioactive dose of oral vitamin B12 in the
urine 24 hours later. When the test was repeated with intrinsic factor, a
greater amount of radioactive B12 was found in the urine 24 hours later. The
diagnosis of PA is supported by the finding of intrinsic factor blocking
antibodies in her blood.
6.
How would the diagnosis change if the special testing results were as follows?
Schilling Test:
Part I, before intrinsic factor: 1%
Part II, after intrinsic factor: 3%
Intrinsic factor blocking antibodies: Negative
The diagnosis is not PA. The vitamin B12 deficiency is due to some other
malabsorption disorder. An abnormal Schilling test result following part II with
oral intrinsic factor and the absence of autoantibodies suggest that the vitamin B12
deficiency was due to some sort of malabsorption disorder such as Crohn’s
disease.
7.
What would you predict the patient’s reticulocyte count to be?
Normal to low. Megaloblastic anemia results from ineffective erythropoiesis
with intramedullary hemolysis, which decreases the normal number of
reticulocytes. In addition, reticulocytosis was not seen in the peripheral
smear.