Transcript nc_archive_81

PEDIATRIC HEMATOLOGY
BOARD REVIEW
Lakshmi Venkateswaran MD
Assistant Professor
Section of Hematology/Oncology
Texas Children’s Hospital/Baylor College of Medicine
June, 2010
RED CELL DISORDERS
NEONATAL ANEMIA
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Hemorrhage:
• Twin-twin / feto-maternal transfusion, overt/external hemorrhage
Hemolysis
• Immune: ABO, Rh, minor blood group incompatibility
• Infection: TORCH, sepsis, parvo virus
• Red cell defects: membrane disorders, enzyme deficiencies,
hemoglobinopathy, micro/macro-angiopathic hemolysis
Underproduction
• Fanconi’s anemia
• Diamond Blackfan anemia
• Schwachman-Diamond syndrome
• Aase syndrome
• Pearson syndrome
• Dyskeratosis congenita
• Congenital Dyserythropoietic anemia
IRON DEFICIENCY ANEMIA
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Cause:
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Dietary (milk based diet - esp. toddlers), blood loss (Meckel’s
diverticulum, GI ulcer, polyps, hemangioma, irritation by cow’s
milk protein, worm infestation), inhibition of/decreased absorption
(lead poisoning, celiac disease, tropical sprue)
Clinical Features:
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Pica, pallor, tachycardia, heart murmur, epithelial changes;
chronic – impaired growth, cognitive dysfunction, altered attention
span, behavior, performance
Lab Features:
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Microcytosis (low MCV), increased RDW, anisocytosis,
poikilocytosis, normal / low reticulocyte count, thrombocytosis
IRON DEFICIENCY ANEMIA
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Differential diagnosis of microcytic anemia:
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Lead poisoning (coarse basophilic stippling, elevated blood
lead level)
Thalassemia trait (MCV disproportionately low, elevated Hb A2,
presence of Bart’s Hb in NB screen)
Anemia of chronic disease (low serum Fe, TIBC, nl or high
ferritin)
Sideroblastic anemia
Congenital anemia with unstable Hb
Management:
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Oral ferrous sulfate
Identify & correct cause
PRBC transfusion – only for severe anemia, with cardiac failure
Parenteral Fe - only in special cases
MEGALOBLASTIC ANEMIA
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Vitamin B12 deficiency
• Dietary – vegan diet (neonate with vegan mother)
• Congenital disorders of absorption & metabolism
• Intrinsic factor defect – gastrectomy, pernicious anemia
• Disorders of ileum
• Folic acid deficiency
• Dietary deficiency (goat’s milk)
• Defects in absorption – small bowel disorders
• Inborn errors of absorption & metabolism
• Drugs – anticonvulsants, methotrexate
• Increased demand – pregnancy, lactation, hemolytic
anemia, prematurity, alcoholism
MEGALOBLASTIC ANEMIA
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Clinical features:
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Macrocytic anemia (high MCV)
low/nl reticulocyte count
neutropenia, thrombocytopenia
hypersegmented neutrophil
megaloblastic bone marrow
Management:
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Vitamin B12 supplementation (oral / parenteral)
Folate supplementation (often oral, rarely parenteral)
Identify and treat the cause
HEMOGLOBINOPATHIES
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Sickle cell disease:
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Beta globin mutation
Sickled RBCs with shortened survival
Lab Features:
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Normocytic anemia
Increased reticulocyte count
Thrombocytosis
Leukocytosis
Peripheral smear: sickle cells, polychromasia, Howell-Jolly
bodies
Hb profile: Hb SS (>50% Hb S); NB screen: FS
SICKLE CELL DISEASE
SICKLE CELL DISEASE
• Clinical Features & management:
• Hand foot syndrome – hydration, analgesics
• Vaso-occlusive crisis – hydration, analgesics
• Acute chest syndrome – hydration, analgesics, oxygen,
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PRBC transfusion, antibiotics
Splenic sequestration crisis – PRBC transfusion,
splenectomy (for recurrent crises)
Aplastic crisis – PRBC transfusion
Splenic dysfunction, sepsis with encapsulated organisms –
broad spectrum cephalosporins, +/- vancomycin, macrolides
Stroke – prevention-TCD screening, exchange transfusion
Priapism – hydration, PRBC transfusion, irrigation, surgery
Education about fever/pain management, spleen palpation
HEMOGLOBINOPATHIES
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Hemoglobin C
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Homozygous – mild anemia, microcytosis; target cells
Hemoglobin SC
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Sickle cell disease; splenomegaly; microcytosis, target &
sickle cells
Hb S / thalassemia
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Beta zero, beta plus, alpha thalassemia
Hemoglobin E
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South East Asia; microcytosis, mild to moderate anemia
THALASSEMIA
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Beta thalassemia: quantitative beta globin
defect
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Thalassemia major
• Severe anemia, transfusion dependent,
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hepatosplenomegaly, characteristic facies
Microcytic, hypochromic anemia, poikilocytes, target
cells
Management – chronic transfusion / iron chelation,
splenectomy, bone marrow transplantation
Thalassemia intermedia
Thalassemia minor
THALASSEMIA
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Alpha thalassemia: quantitative alpha globin
defect
• One gene
• Silent carrier
• Two genes
• Thalassemia trait (microcytosis, mild anemia, Hb Bart’s in
NB screen)
• Three genes
• Hb H disease (moderate hemolytic anemia, Hb Bart’s in
NB screen, Hb H in Hb profile)
• Four genes
• Hydrops fetalis
THALASSEMIA
HEMOLYTIC ANEMIA
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Intrinsic
• Hereditary spherocytosis
• Mild, moderate, severe
• Increased MCHC, spherocytes, increased osmotic fragility,
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reticulocytosis
Transfusion, splenectomy
• Hereditary elliptocytosis
• G6PD deficiency
• Seen in African American, Asian, Arabic, Mediterranean population
• Mild-severe; hemolysis triggered by food/drugs (fava beans,
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bactrim, naphthalene, anti-malarials), infections
Prevent exposure, transfusion
• Pyruvate Kinase deficiency
HEMOLYTIC ANEMIA
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Extrinsic
• Paroxysmal cold hemoglobinuria
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Autoimmune hemolytic anemia
• Idiopathic or secondary
• Often preceded by viral infection
• Acute hemolysis, severe anemia, reticulocytosis,
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hyperbilirubinemia, hemoglobinuria
Mild splenomegaly
Coomb’s test positive
Steroids, transfusion
BONE MARROW FAILURE
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Congenital disorders – Macrocytic anemia
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Fanconi’s anemia - rash, skeletal (thumb), cardiac, renal
anomalies; supportive care, BMT
Diamond-Blackfan anemia – pure red cell aplasia, macrocytic,
reticulocytopenic; prednisone, BMT
Transient Erythroblastopenia of childhood
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Normo/macrocytic anemia, reticulocytopenia; may follow viral
infection; self-resolving
Acquired aplastic anemia
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Macrocytic anemia, pancytopenia
Bleeding, infections
BMT, immunosuppressive therapy
POLYCYTHEMIA
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Primary
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Polycythemia vera
Familial polycythemia
Secondary
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Pulmonary disease
Cardiac disease
Renal disorders
Tumors – Wilm’s, liver, adrenal gland, cerebellum, uterus,
ovary
Endocrine imbalance – excess steroids, androgens, growth
hormone
Q&A
1. On a routine-screening complete blood count, a 1-yearold is noted to have a microcytic anemia. A follow-up
hemoglobin electrophoresis demonstrates an increased
concentration of hemoglobin A2. The child is most likely
to have
 a. Iron deficiency
 b. β-thalassemia trait
 c. Sickle cell anemia
 d. Chronic systemic illness
 e. Lead poisoning
Q&A
2. A 15 month old infant has been breast fed since birth. He
now eats finger foods (carrot, peas etc) and some
cereal. His mother is a strict vegan and plans to
continue the child on a similar diet.
A complete blood count documents anemia. What is the
most likely cause of anemia?
a.
Niacin
b.
Folic acid
c.
Riboflavin
d.
Thiamine
e.
Vitamin B12
Q&A
3. A 4-year-old previously well boy develops pallor, dark urine,
and jaundice. There has been no apparent exposure to a
jaundiced person or to any toxins. He is taking trimethoprimsulfamethoxazole for otitis media. You consider the
possibility of a hemolytic crisis caused by glucose-6phosphate dehydrogenase (G6PD) deficiency. In which of
the following ethnic groups is the incidence lowest?
 a. African American
 b. Greek
 c. Chinese
 d. Middle Eastern
 e. Scandinavian
Q&A
4. On a routine newborn screen, a 2-week-old child in your
clinic is noted to have sickle cell disease. As you discuss
treatment options with this family, you recommend
 a. Monthly injections of vitamin B12
 b. Tetracycline prophylaxis
 c. Meningococcal vaccine at 2, 4, and 6 months of age
 d. Education of parents regarding abdominal palpation
and temperature taking
 e. Infusion of immunoglobulin every 6 weeks
Q&A
5. A preterm black male infant was found to be jaundiced 12
h after birth. At 36 h of age, his serum bilirubin was 18
mg/dL, hemoglobin concentration was 12.5 gm/dL, and
reticulocyte count 9%. Many nucleated red cells and
some spherocytes were seen in the peripheral blood
smear. The differential diagnosis should include which of
the following?
 a. Pyruvate kinase deficiency
 b. Hereditary spherocytosis
 c. Sickle cell anemia
 d. Rh incompatibility
 e. Polycythemia
Q&A
6. On a routine well-child examination, a 1-year-old boy is
noted to be pale. He is in the seventy-fifth percentile for
weight and the twenty-fifth percentile for length. Results
of physical examination are otherwise normal. His
hematocrit is 24%. Of the following questions, which is
most likely to be helpful in making a diagnosis?
 a. What is the child’s usual daily diet?
 b. Did the child receive phototherapy for neonatal
jaundice?
 c. Has anyone in the family received a blood transfusion?
 d. Is the child on any medications?
 e. What is the pattern and appearance of his bowel
movements?
Q&A
7. Having performed a complete history and physical examination on the
patient, you proceed with a diagnostic workup. Initial laboratory results
are as follows: hemoglobin 8 gm/dL; hematocrit 24%; leukocyte count
11,000/Μl with 38% neutrophils, 7% bands, 55% lymphocytes;
hypochromia on smear; lead level 7 μg/dL whole blood; platelet count
adequate; reticulocyte count 0.5%; sickle cell preparation negative;
stool guiac negative; and mean corpuscular volume (MCV) 65fl. You
would most appropriately recommend
 a. Blood transfusion
 b. Oral ferrous sulfate
 c. Intramuscular iron dextran
 d. An iron-fortified cereal
 e. Calcium EDTA
Q&A
8. A 10 y/o girl c/o increasing fatigue several days after suffering from
an URI. Findings on PE include obvious pallor, scleral icterus and
spleen tip palpable 3 cm below costal margin. Laboratory studies
reveal Hb of 6.3 gm/dl, retic count of 10% and indirect bilirubin of
2.8 mg/dl. Rest of the blood count is wnl. Past medical history is
unremarkable. She has had a normal Hb at 1 year of age and has
not had any lab tests until this visit.
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Of the following, in addition to the CBC, the most appropriate lab
test to order in this patient is
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A. G6PD assay
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B. Direct Coomb’s test
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C. Osmotic fragility
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D. Haptoglobin concentration
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E. Hemoglobin electrophoresis
Q&A
9. A 2950-g black baby boy is born at home at term. On
arrival at the hospital, he appears pale, but the physical
examination is otherwise normal. Laboratory studies
reveal the following: mother’s blood type A, Rh positive;
baby’s blood type O, Rh positive; hematocrit 38%;
reticulocyte count 5%. Which of the following is the most
likely cause of the anemia?
 a. Fetomaternal transfusion
 b. ABO incompatibility
 c. Physiologic anemia of the newborn
 d. Sickle cell anemia
 e. Iron-deficiency anemia
Q&A
10. An 8-year-old patient with sickle cell anemia
11. A 7-month-old boy with severe anemia requiring
transfusions, heart failure, hepatosplenomegaly, and
weakness
12. A 3-day-old newborn with anemia and pathologic
hyperbilirubinemia requiring phototherapy
13. A completely asymptomatic, healthy 1-year-old
whose routine CBC reveals an abnormality.
Q & A – a,b
Q & A – c,d
WHITE CELL DISORDERS
NEUTROPENIA
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Intrinsic defects:
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Reticular dysgenesis
Cyclic neutropenia
Severe congenital neutropenia (Kostmann disease)
Myelokathexis and WHIM syndrome
Schwachman-Diamond syndrome
Chediak-Higashi syndrome
Familial benign neutropenia
Bone marrow failure syndromes (congenital 7 acquired)
CYCLICAL NEUTROPENIA
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Sporadic or autosomal dominant
Regular, periodic oscillations (every 21 days; range 14-36 days)
of neutrophils (rarely other cells as well)
Nadir <200cells/microL
S/s: fever, oral ulcers, gingivitis, periodontitis, pharyngitis,
lymph node enlargement
Severe: mastoiditis, pneumonia, vaginal/rectal ulcers,
peritonitis; ~10% mortality
Bone marrow: Hypoplasia or arrest at myelocyte stage
ELA-2 mutations
Management: GCSF
SEVERE CONGENITAL
NEUTROPENIA
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Autosomal recessive inheritance
Incidence 2 per million
ANC < 200 cells/microL
Recurrent infections (skin, stomatitis, pneumonia, peri-rectal
abscess; Staph aureus, E. coli, Pseudomonas sepsis)
Bone marrow exam: arrest at promyelocyte / myelocyte stage
ELA-2 gene mutations
May develop MDS/ AML
Management: GCSF (risk for leukemia) / BMT
SCHWACHMAN-DIAMOND
SYNDROME
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Clinical features:
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Neutropenia (moderate to severe), recurrent infections,
exocrine pancreatic insufficiency (diarrhea), growth
retardation / short stature, metaphysial chondrodysplasia /
skeletal abnormalities
SDS gene mutation ~90% of patients
Bone marrow:
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Decreased myeloid precursors
Cancer predisposition syndrome, can progress to
bone marrow failure
Management: GCSF, BMT, pancreatic enzyme
supplement
CHEDIAK-HIGASHI
SYNDROME
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Autosomal recessive inheritance
Clinical features:
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Partial oculo-cutaneous albinism, recurrent infections,
cranial & peripheral neuropathies; hepatosplenomegaly &
pancytopenia in accelerated phase
Diagnosis:
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Giant lysosomes in peripheral blood granulocytes & BM
myeloid precursors cells
CHS gene mutations
Management: treat infections, ascorbic acid, BMT
NEUTROPENIA
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Extrinsic defects:
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Infection
Drugs
Autoimmune neutropenia
Chronic benign neutropenia of childhood
Associated with immune dysfunction
Associated with metabolic diseases
Nutritional deficiencies
Reticuloendothelial sequestration
Bone marrow infiltration
Chronic idiopathic neutropenia
CHRONIC BENIGN NEUTROPENIA
OF CHILDHOOD
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Most common cause
Median age 8-11 months (range 3-38 months)
ANC 0-500
May last for several months (median 20; range 6-54
months)
Diagnosis:
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Anti-neutrophil antibody usually positive
BM exam: Maturation arrest at earlier stages
Management:
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Treat infections, counsel parents
Rarely GCSF
Reassurance - Self-resolving
NEONATAL ALLOIMMUNE
NEUTROPENIA
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Analogous to Rh hemolytic disease
May last for several weeks to 6 months
Diagnosis:
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Mother - NA1 & NA2 antigen negative; antibody positive
Father & patient antigen positive
Self-resolving
Management:
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Treat infections
May consider GCSF
NEUTROPHILIA
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Acute / Chronic infection
Chronic inflammation
Tumors
Myeloproliferative disorders
Drugs (lithium, ranitidine, corticosteroids)
Leukemoid reactions
Post-neutropenia rebound
Chronic idioapthic neutrophilia
Familial cold urticaria
Splenectomy
Leukocyte adhesion deficiency
Stress, exercise, epinephrine
Hypoxia
Q&A
14. An otherwise healthy child
has on his 1-year-old routine
CBC the polymorphonuclear
neutrophil shown in the
following illustration. This
child likely has
 a. Malignancy
 b. Iron deficiency
 c. Folic acid deficiency
 d. Dohle inclusion bodies
 e. The Pelger-Huet nuclear
anomaly
Q&A
15. A 12 month old infant presents with 3 day history of rhinorrhea,
decreased appetite and temperature of 101.5 C. On PE, the
child is happy, playful and has no other findings except
rhinorrhea. Since 8 months of age, the CBC has consistently
shown WBC count of 2400 to 3000 (2.4 - 3x109/L), and ANC
less than 400. A bone marrow exam at 11 months showed
granulocytopenia with normal trilineage precursors. Besides
occasional cold, the child has not had any serious infections.

Of the following, the management strategy that is most
appropriate is
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A. Allogenic BMT
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B. IVIG
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C. Prophylactic antibiotic therapy
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D. GCSF
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E. Symptomatic supportive care
EOSINOPHILIA
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Allergic disorders: Asthma, hay fever, urticaria, drug reaction, acute
bronchopulmonary aspergillosis
Dermatitis: Atopic dermatitis, pemphigus, pemphigoid
Infections: Invasive parasites, PCP, Toxoplasmosis, Malaria,
Scabies, Coccidioidomycosis
Tumors: Brain tumors, Hodgkin / NHL, myeloproliferative disorders,
eosinophilic leukemia
Hereditary eosinophilia
GI disorders: Regional enteritis, milk precipitin disease
Hypereosinophilic syndromes
Miscellaneous: Immunodeficiency disorders
MONOCYTOSIS
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Hematologic disorders
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Leukemia / lymphoma, neutropenia
Collagen vascular disorder
Granulomatous disease
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Ulcerative colitis, regional enteritis, sarcoidosis
Infection
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Subacute bacterial endocarditis, Tuberculosis, syphilis,
protozoal / rickettsial infections; FUO
Post-splenectomy state
Q&A
16. During a routine-screening CBC, a 1-year-old is
noted to have eosinophilia. Which of the following
most likely will cause increased eosinophilia in the
peripheral blood smear?
 a. Bacterial infections
 b. URI
 c. Fungal infections
 d. Invasive parasitic infestation
 e. Tuberculosis
CONGENITAL PLATELET
DISORDERS
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Quantitative
• Thrombocytopenia absent radius syndrome
• Neonate with absent radius, platelet count improves after 1
year
• Amegakaryocytic thrombocytopenia
• Bone marrow failure; isolated thrombocytopenia, may
progress to pancytopenia / MDS; management – BMT
• Wiskott-Aldrich syndrome
• X-linked recessive; triad of immunodeficiency, eczema,
thrombocytopenia (small platelets)
• Congenital macrothrombocytopenia (MYH 9 disorder)
• May-Hegglin & others; large to giant platelets; some have
Dohle bodies; may have renal, eye (cataract), hearing defects
CONGENITAL PLATELET
DISORDERS

Qualitative
• Glanzmann thrombasthenia
• Normal platelet count, bleeding since infancy; Gp IIb/IIIa
defect; platelet transfusion for major bleeds / rF VIIa
• Bernard-Soulier syndrome
• Thrombocytopenia; Gp Ib/IX defect; platelet transfusion for
major bleeds / rF VIIa
• Gray platelet syndrome
• Absence of platelet granules
• Storage pool disorder
• Platelet secretion defect
ACQUIRED PLATELET
DISORDERS
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Acquired thrombocytopenia
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Immune thrombocytopenic purpura
• Immune mediated, may follow viral infection,
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vaccination
Destruction of antibody coated platelets
Physical exam – normal except petechiae, bruises
Lab features: Isolated thrombocytopenia, mixture of
normal and large platelets
Diagnosis of exclusion, BMA not necessary in typical
cases
Management: steroids, IVIG; platelet transfusion only
for life threatening bleeding
ACQUIRED PLATELET
DISORDERS
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Acquired thrombocytopenia
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Neonatal alloimmune thrombocytopenia (NAIT)
• Platelet equivalent of Rh disease
• Mother HPA1a negative, father & patient positive
• Moderate to severe thrombocytopenia
• Increased risk for intracranial bleeding
• Test mother & father for platelet antigen
•
•
incompatibility
Treatment: antenatal – IVIG/prednisone; post-natal –
random donor/maternal platelets, IVIG
Counsel for future pregnancies
ACQUIRED PLATELET
DISORDERS
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Acquired thrombocytopenia
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Infections – DIC, viral, fungal infections
Drugs
Microangiopathic – hemolytic uremic syndrome / TTP
Hypersplenism
Vitamin B12, folate, Fe deficiency
Polycythemia
Liver disease
Kassabach-Merritt syndrome
Cardiac prosthesis, cardiopulmonary bypass
Aplastic anemia
Leukemia
Hypothermia
Q&A
17.Two weeks after a viral syndrome, a 2-year-old child develops
bruising and generalized petechiae, more prominent over the
legs. No hepatosplenomegaly or lymph node enlargement is
noted. The examination is otherwise unremarkable. Laboratory
testing shows the patient to have a normal hemoglobin,
hematocrit, and white blood count and differential. The platelet
count is 15,000/μL. The most likely diagnosis is
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a. von Willebrand disease
b. Acute leukemia
c. Idiopathic (immune) thrombocytopenic purpura
d. Aplastic anemia
e. Thrombotic thrombocytopenic purpura
Q&A
18. Appropriate treatment of this child includes
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a. Intravenous gamma globulin
b. Platelet transfusion
c. Aspirin therapy
d. Factor VIII infusion
e. Prednisone, vincristine, and asparaginase induction
followed by methotrexate
and 6-mercaptopurine
Q&A
19. A newborn infant is born with petechiae scattered
across his body. His platelet count is noted to be
22,000/μL with a hemoglobin of 12 mg/dL. Which of
the following is most likely to explain this infant’s
condition?
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a. Congenital cytomegalovirus infection
b. Uncomplicated prematurity
c. Chlamydial conjunctivitis
d. Maternal ingestion of aspirin
e. Nasolacrimal duct stenosis
Q&A
20. A 3-year-old child presents with a petechial rash but is
otherwise well and without physical findings. Platelet
count is 20,000/μL; hemoglobin and WBC count are
normal. The most likely diagnosis is
 a. Immune thrombocytopenic purpura (ITP)
 b. Henoch-Schonlein purpura
 c. Disseminated intravascular coagulopathy (DIC)
 d. Acute lymphoblastic leukemia
 e. Systemic lupus erythematosus (SLE)
Q&A
16. A male infant is born without right thumb. Lab
testing reveals platelet count of 60x109/L. Of the
following the best management of this patient is

a. Bone marrow biopsy

b. Computed tomography of head

c. Genetics consultation

d. Intravenous corticosteroid therapy
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e. Intravenous immunoglobulin therapy
THROMBOCYTOSIS
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Inflammation
Infection (commonly seen after viral infections)
Acute & chronic bleeding
Iron, vitamin E deficiency
Hemolytic anemia
Asplenia
Malignancy
Drugs (epinephrine, vinca alkaloids)
Nephrotic syndrome
Graft-versus-host disease
Kawasaki disease
Essential thrombocythemia - rare
COAGULOPATHY
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Congenital disorders
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Hemophilia A, B, C
• Clotting factor (8,9,11) deficiency
• Mild, moderate, severe
• Post-circumcision bleeding, epistaxis, soft tissue
•
•
bleed, muscle hematoma, hemarthrosis, posttraumatic / surgical bleeding, intra-cranial bleeding
Lab features: PTT prolonged, low factor level
Management: Factor replacement, education,
physical therapy, prevention, prophylaxis
COAGULOPATHY
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Congenital disorders
•
Von Willebrand disease
• Deficient or defective von Willebrand antigen
• Type I, II (A, B, M, N), III
• Lab test: PTT may be prolonged; abnormalities of
•
•
•
von
Willebrand antigen / activity / multimer; low platelet count
in type 2B
Type I – common; epistaxis, mucosal bleeding,
menorrhagia, post-traumatic/surgical bleeding
Treatment – DDAVP/Stimate, factor replacement
(Humate P)
Type II, III – severe, need factor replacement (Humate P)
COAGULOPATHY
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Acquired disorders
• DIC – prolonged PT, PTT, low fibrinogen,
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•
•
•
thrombocytopenia, elevated D dimer / fibrin split
products
Drugs – anticoagulants
Antibodies to clotting factors
Liver disease – prolonged PT, PTT, low fibrinogen
Vitamin K deficiency
• Clotting factors 2,7,9,10
• Hemorrhagic disease of newborn, malabsorption / chronic
diarrhea, cystic fibrosis, drugs (anticonvulsants, antibiotics)
• Lab features: prolonged PT, PTT, normal fibrinogen, platelet
count
• Management: vitamin K (oral/parenteral), FFP (acute bleeding)
Q&A
22. A 2-year-old child in
shock has multiple
nonblanching purple
lesions of various sizes
scattered about on the
trunk and extremities;
petechiae are noted, and
oozing from the puncture
site has been observed.
The child’s peripheral
blood smear is presented.
Clotting studies are likely
to show which of the
following?
Q&A
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a. Increased levels of factor V and VIII
b. A decreased prothrombin level
c. An increased fibrinogen level
d. The presence of fibrin split products
e. Normal partial thromboplastin time (PTT)
Q&A
23. A 10-year-old boy is admitted to the hospital because of
bleeding. Pertinent laboratory findings include a platelet
count of 50,000/μL, prothrombin time (PT) of 15 s (control
11.5 s), activated partial thromboplastin time (aPTT) of 51
s (control 36 s), thrombin time (TT) of 13.7 s (control 10.5
s), and factor VIII level of 14% (normal 38 to 178%). The
most likely cause of his bleeding is
 a. Immune thrombocytopenic purpura (ITP)
 b. Vitamin K deficiency
 c. Disseminated intravascular coagulation (DIC)
 d. Hemophilia A
 e. Hemophilia B
Q&A
24. A term infant who was delivered at home is
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breastfeeding poorly. She is referred to you 7 days after
birth by a lactation consultant because of bleeding from
the umbilical cord and blood in stool. Findings on PE are
normal, there are no petechiae, purpura,
hepatosplenomegaly or neurologic abnormality.
Of the following, the most likely diagnosis is
A. DIC
B. Neonatal alloimmune thrombocytopenia
C. Classic vitamin K deficiency
D. von Willebrand disease
E. Factor VIII deficiency
THROMBOSIS
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Venous or arterial
Cause:
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•
•
•
Central venous access device – most common
Idiopathic
Inherited thrombophilic conditions: protein C/S, antithrombin deficiency, factor V Leiden, prothrombin G20210A
mutation, MTHFR mutation, elevated lipoprotein a
Acquired conditions: Infections (MRSA), malignancy,
trauma, systemic lupus erythematosus, nephrotic syndrome,
protein losing enteropathy, congenital heart disease,
prolonged immobilization
THROMBOSIS

Clinical features:
•
•
•
•

Deep venous thrombosis – swelling, pain, discoloration
Stroke
Pulmonary embolism – cough, shortness of breath, hypoxia,
cyanosis
Arterial thrombosis: pain, pallor, swelling,
ischemic/gangrenous changes, organ dysfunction
Diagnosis
•
•
•
Gold standard – contrast angiography – rarely done
Ultrasound – Doppler
MRV/MRA, CT angiography, echocardiography, V/Q scan
THROMBOSIS MANAGEMENT

Anti-thrombotic therapy:
•
•


Anticoagulants – unfractionated heparin, low molecular
weight heparin, vitamin K antagonists (coumadin), others
Thrombolytic agents – tPA
Mechanical thrombectomy
Surgical thrombectomy
ANSWERS
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1. b
2. e
3. e
4. d
5. b
6. a
7. b
8. b
9. a
10. c
11. d
12. a
13. b
14. c
15. e
16. d
17. c
18. a
19. a
20. a
21. c
22. d
22. c
24. c