Hematology

Question 1

What is the differential diagnosis for a microcytic anemia with a low reticulocyte count?

Answer 1

Iron deficiency
Thalassemia trait
Chronic disease/inflammation
Lead poisoning
Sideroblastic anemias
Copper deficiency 
Iron refractory iron deficiency anemia

Question 2

What is the differential diagnosis for a normocytic anemia with a low/inadequate reticulocyte count?

Answer 2

Chronic disease/inflammation
RBC aplasia (TEC, infection, drugs)
Malignancy
Endocrinopathies
Renal failure 
Acute bleeding
Hypersplenism

Question 3

What is the differential diagnosis for a normocytic anemia with a high reticulocyte count?

Answer 3

Antibody mediated hemolysis
Hypersplenism
Microangiopathy (HUS, TTP, DIC, Kasalbach-Merritt)
Membranopathies (sperocytosis, elliptocytosis, ovalocytosis)
Enzymopathies (G6PD, PK, deficiencies)
Hemoglobinopathies (HbSS, SC)

Question 4

What is the differential diagnosis for a macrocytic anemia with a low/inadequate reticulocyte count?

Answer 4

Folate deficiency
Vitamin B12 deficiency
Acquired aplastic anemia
Congenital aplastic anemia (Diamond-Blackfan, Fanconi Anemia)
Drug induced
Trisomy 21
Hypothyroidism
Liver disease
Myelodysplasias
Drugs

Question 5

What ethnicity is most associated with hereditary spherocytosis?

Answer 5

Northern European origin

Question 6

What are the defining features of Transient Erythroblastopenia of Childhood (TEC)?

Answer 6

• 6mo-3yo (usually DBA presents <1yr)
• Often follows viral illness
• Normocytic anemia with low/inadequate reticulocytes
• Normal RBC adenosine deaminase levels (elevated in DBA)
• 20% have co-occurring neutropenia
• Majority recover in 1-2 months

Question 7

A 5 yo child presents with renal stones, splenomegaly and a hemolytic anemia. They have a history of jaundice as a neonate requiring phototherapy. There is a family history of a hemolytic anemia but the family doesn’t remember the name. What test would help you to confirm your leading diagnosis?

Answer 7

Peripheral smear for spherocytes.

Hereditary Spherocytosis

• AD (25% de novo/recessive)
• Most common in N. Europeans
• Neonates often have hyperbili and need PTx, exchange Tx
• Bilirubin gallstones age 4-5
• Hemolytic anemia with reticulocytosis & indirect hyperbili
• Dx: +FHx, splenomegaly, spherocytes, hemolytic anemia

Question 8

What is the mentzer index? How do you calculate and interpret?

Answer 8

MI = to differentiate Fe deficiency from thalassemia trait
MI = MCV/RBC
-If >13 = Fe deficiency anemia
-If<13 = Thalassemia

Question 9

What features may help to differentiate Diamond Blackfan Anemia from TEC?

Answer 9

DBA/TEC:

• Presents: Infancy (2-6mths)/1-4years
• Macrocytic/Normocytic
• Elevated Hb F (stress erythropoiesis)/No elevation in Hb F
• Erythrocyte deaminase activity may be elevated/No elevation in erythrocyte deaminase activity
• DBA may also have congenital anomalies

Question 10

What is the classical triad of Fanconi anemia?

Answer 10

Bone marrow failure: thrombocytopenia, RBC macrocytosis and increased HbF appear first (due to BM stress)
Elevated chromosome fragility
Congenital anomalies
-Most common are skeletal and include absence of radii +/- abN thumbs
-Skin hyperpigmentation
-Short stature
-GU anomalies
-Microcephaly, small eyes, epicanthal folds, abN ears

Question 11

What are the two main features in a clinical diagnosis of Swachman-Diamond Syndrome?

Answer 11

Bone marrow dysfunction and exocrine pancreatic insufficiency (Remember the S in SDS = Steatorrhea!).

• 90% have neutropenia
• 98% have exocrine pancreatic insufficiency
• Also, there is NO chromosomal breakage
• Classic skeletal anomalies: metaphyseal dysplasia, osteopenia, short flared ribs, thoracic dystrophy

Question 12

A 2yo child presents with severe seborrheic dermatitis of the scalp as well as eczematous rash to the groin and abdomen. Labs show cytopenias and a skull x-ray reveals lytic lesions. What diagnosis comes to mind?

Answer 12

Langerhan’s Cell Histiocytosisis

• Lytic bone lesions
• Seborrheic dermatitis/brown-purple papules/eczematous rash
• Lymphadenopathy
• Enlarged thymus (airway compression)
• Bone marrow; pancytopenia
• Hepatic involvement
• Massive splenomegaly
• Lung nodules
• Central DI
• Thickened pituitary stalk

Question 13

What do you hope to prevent with irradiated blood products?

Answer 13

This is indicated for those with impaired T cell function. The goal is to prevent transfusion associated GVHD.

Question 14

What is the iron supplementation recommendation for LBW infants?

Answer 14

For LBW infants (<2.5kg) who are predominantly breastfed (>50% of intake), Fe supp. is routinely recommended:
-BW 2-2.5kg: 1-2mg/kg/day for 0-6months
-BW <2kg: 2-3mg/kg/day for 0-12months
Fe supp. NOT required for LBW infants fed preterm formulas that are higher in Fe