Here are the explanations for questions on the hematopathology quiz.
1. A patient is found to have a decreased hemoglobin and an increased mean cell volume
(MCV). Which of the following is the most likely diagnosis?
A. Iron deficiency
B. Thalassemia
C. Anemia of chronic disease
D. Vitamin B12 or folate deficiency*
The only anemia with an increased MCV on the list is anemia due to B12 or folate deficiency.
This type of anemia is a macrocytic (MCV>100) anemia. Iron deficiency anemia and thalassemia
are both microcytic (MCV<80), and anemia of chronic disease is either microcytic or normocytic.
2.All of the following statements are true regarding vitamin B12/folate deficiency anemia
EXCEPT:
A.It is characteristically a macrocytic anemia
B.Vitamin B12 stores in the body generally last for 3 months without replenishment*
C.The hallmarks of the blood smear include macrocytes (large red blood cells) and
hypersegmented neutrophils
D.Folate deficiency anemia is frequently seen in chronically malnourished individuals such as
alcoholics
B12 stores last way longer than 3 months without replenishment, because B12 is recycled. If you
totally quit eating B12, it would take a few years to become B12 deficient. Folate is another
story - you can become folate deficient within a period of a few months (a situation most
common in malnourished patients and alcoholics).
3.A patient presents with a decreased hemoglobin and a decreased mean cell volume (MCV).
The neutrophil and platelet count are normal. Which of the following is the most likely
diagnosis?
A.Vitamin B12 or folate deficiency
B.Aplastic anemia
C.Sickle cell anemia
D.Either iron deficiency or thalessemia*
Both iron deficiency anemia and thalassemia are microcytic (and both should show a normal
neutrophil and platelet count). A is wrong because anemia due to B12/folate deficiency is
megaloblastic. B is wrong because in aplastic anemia, there is a pancytopenia (decreased
numbers of red cells, white cells, and platelets), and the anemia is usually normocytic. C is
wrong because sickle cell anemia is a normochromic anemia, and the neutrophil and platelet
count are not typically decreased in this anemia.
4.Which of the following sets of lab values best fits sickle cell anemia?
A. Hgb decreased, MCV decreased, reticulocyte count decreased
B. Hgb normal, MCV normal, reticulocyte count normal
C. Hgb decreased, MCV increased, reticulocyte count decreased
D. Hgb decreased, MCV normal, reticulocyte count increased*
E. Hgb normal, MCV decreased, reticulocyte count decreased
In sickle cell anemia, the hemoglobin is decreased (the definition of anemia!), the MCV is normal,
and the reticulocyte count is increased (assuming the bone marrow has the capacity to make
red cells at an increased rate to make up for the cells bursting open and getting stuck in little
vessels.
5.Which of the following sets of lab values best fits iron-deficiency anemia?
A. Hgb decreased, MCV decreased, reticulocyte count decreased*
B. Hgb normal, MCV normal, reticulocyte count normal
C. Hgb decreased, MCV increased, reticulocyte count decreased
D. Hgb decreased, MCV decreased, reticulocyte count increased
E. Hgb normal, MCV decreased, reticulocyte count decreased
In iron-deficiency anemia, the hemoglobin is decreased (as in any anemia), the MCV is
decreased (IDA is a microcytic anemia) and the reticulocyte count is decreased (since the whole
problem is that there is not enough iron around to make red cells). Once you give the patient
iron, the retic count will start going up.
6.Which of the following is true regarding leukemia?
A. Acute lymphoblastic leukemia (ALL) is more common than acute myeloid leukemia (AML) in
children*
B. Chronic leukemias are composed mostly of blast cells
C. CML is most common in children
D. Acute leukemia is generally not accompanied by bone marrow failure (i.e. thrombocytopenia,
anemia and neutropenia)
ALL is the most common kind of leukemia in children. Children can get AML too, but it's much
less common. And kids never get chronic leukemias (so C is wrong). B is wrong, because chronic
leukemias are composed of maturing cells, not blasts, like you see in acute leukemias. D is
wrong because acute leukemia most often is accompanied by some degree of bone marrow
failure (decreases in all three main cell lines).
7. Which of the following is or are true regarding acute myeloid leukemia (AML)?
A. A patient with l5% myeloblasts in the blood or bone marrow can be diagnosed as having
AML
B. Myeloblasts typically express myeloperoxidase (MPO) enzyme*
C. Both
D. Neither
A is wrong because you need at least 20% blasts to call it AML. B is right - in most cases of AML,
myeloblasts express MPO (you can stain for it using an MPO stain). The one exception is AMLM0 (acute myeloblastic leukemia with minimal differentiation), the myeloblasts don't express
MPO. They're just too dang undifferentiated...you can hardly tell which lineage (myeloid or
lymphoid) they've committed to, because they don't have Auer rods and they don't stain for
MPO (they do have a few granules on electron microscopy though!).
8. Infiltrates of the gingiva are particularly characteristic of which of the following leukemias?
A. Chronic myelogenous leukemia (CML)
B. Acute monoblastic leukemia (AML-M5A)*
C. B-cell acute lymphoblastic leukemia
D. Chronic lymphocytic leukemia
Any malignant process with a lot of monocytes has a higher risk of extramedullary involvement gums, testes, skin, and CNS are the most common sites. Both of the AML-M5s (M5A and M5B)
as well as AML-M4 have monocytes - so patients with these types of AML are closely monitored
for extramedullary spread. They typically get extra chemotherapy in the spinal fluid to prevent
leukemic spread there.
9.The Philadelphia chromosome involves a translocation between chromosomes _____ and is
always present in ______.
A. 8 and 21; acute myeloid leukemia (AML)
B. 8 and 21; chronic myeloid leukemia (CML)
C. 9 and 22; AML
D. 9 and 22; CML*
The Philadelphia chromosome is a translocation between the bcr gene on chromosome 9 and
the abl gene on chromosome 22. It is present in all cases of CML, and doesn't show up in AML.
10. Which of the following is true regarding Hodgkin's disease?
A. It frequently arises in the intestines
B. It responds poorly to current chemotherapeutic regimens
C. It tends to spread in a contiguous fashion*
D. It typically presents only in elderly patients
Unlike non-Hodgkin lymphoma (which tends to skip around - it's in a lymph node, then in the
bone marrow, then in another node, for example...), Hodgkin lymphoma (or disease) spreads in
a contiguous fashion from one node to the next along lymph node chains (at least in the early
stages). That's one reason it is easier to treat (it responds well to radiation and chemo, usually).
It usually arises in a lymph node (A is wrong). It frequently occurs in younger patients - in fact, it
has two peaks: one in patients aged 15-35 and one in patients over 55 (so D is wrong).
11.All of the following statements are true regarding lymphoma EXCEPT:
A. Hodgkin's lymphoma generally has a good prognosis
B. The malignant cell of Hodgkin's lymphoma is the Reed-Sternberg cell
C. Low grade lymphomas frequently can be cured by chemotherapy*
D.Follicular lymphomas are all B-cell lymphomas
C is the correct answer because although they are not aggressive, low grade lymphomas are
generally not curable by traditional chemotherapeutic agents. It's a weird paradox: low-grade
disease/incurable, high-grade disease/potentially curable. The reason is because standard
chemotherapeutic agents target dividing cells - and the cells of low-grade lymphoma are not
dividing all that fast (they're just accumulating!). The cells of high-grade lymphomas are turning
over rapidly - so there is the potential for cure with chemotherapy (the overall prognosis is still
poor, though). A is true. So is B. D is true too...in fact, most non-Hodgkin lymphomas are of Bcell origin (notable exceptions being mycosis fungoides/Sezary syndrome and anaplastic T-cell
lymphoma).
12. Which of the following is a LOW grade lymphoma?
A. Follicular lymphoma*
B. Diffuse, large B-cell lymphoma
C. Burkitt lymphoma
D. Anaplastic large-cell lymphoma
Pretty self-explanatory. B, C, and D are all aggressive, fast-growing, poor-prognosis lymphomas.
13.All of the following statements are true regarding myeloma EXCEPT:
A. Characterized by a clonal proliferation of plasma cells
B. Often produces lytic lesions especially of skull
C. Bone marrow shows histiocytes with Birbeck granules*
D. Associated with monoclonal gammopathy
Myeloma is characterized by a malignant, clonal proliferation of plasma cells which (being
clonal) all make the same exact kind of immunoglobulin (thus leading to a monoclonal
gammopathy). Lytic lesions are a characteristic feature of the disease (as are anemia and renal
failure). Histiocytes with Birbeck granules are seen in a totally different disease called
histiocytosis X.