ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
ASCP RECALL EXAM
2026–2027 | Updated Study Guide | Verified Edition
100% Accurate & Verified Questions and Answers | ASCP BOC Examination Content Aligned
100 Questions | 7 Clinical Laboratory Science Domains
Section 1: Hematology (Q1–Q20)
Section 2: Clinical Chemistry (Q21–Q40)
Section 3: Microbiology (Q41–Q55)
Section 4: Blood Bank / Immunohematology (Q56–Q70)
Section 5: Immunology and Serology (Q71–Q80)
Section 6: Urinalysis and Body Fluids (Q81–Q90)
Section 7: Laboratory Operations and Quality (Q91–Q100)
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
SECTION 1: Hematology (Q1–Q20)
CBC Parameters | Anemias | WBC Disorders | Platelets | Coagulation |
Hemoglobinopathies | Bone Marrow
Q1. A patient's CBC shows: Hgb 7.2 g/dL, MCV 58 fL, RDW 18% (elevated), serum iron 28
mcg/dL, TIBC 490 mcg/dL, ferritin 6 ng/mL. What is the MOST likely diagnosis?
A. Anemia of chronic disease
B. Iron deficiency anemia
C. Beta-thalassemia trait
D. Sideroblastic anemia
CORRECT ANSWER: B
Rationale: The combination of low hemoglobin, microcytic (low MCV), elevated RDW (high degree of
anisocytosis), low serum iron, elevated TIBC (body seeking iron), and critically low ferritin (depleted iron
stores) is the classic profile of iron deficiency anemia. Anemia of chronic disease shows low iron but also low
TIBC and normal/high ferritin. Beta-thalassemia trait has low/normal RDW and normal iron studies.
Sideroblastic anemia shows elevated serum iron and ringed sideroblasts on bone marrow.
Q2. A peripheral blood smear from a patient with severe hemolytic anemia shows numerous
schistocytes, microspherocytes, and thrombocytopenia. Laboratory values show elevated LDH,
elevated indirect bilirubin, and decreased haptoglobin. This constellation is MOST consistent
with:
A. Iron deficiency anemia
B. Thrombotic thrombocytopenic purpura (TTP)
C. Warm autoimmune hemolytic anemia
D. Aplastic anemia
CORRECT ANSWER: B
Rationale: TTP is characterized by the pentad: microangiopathic hemolytic anemia (schistocytes, elevated
LDH, decreased haptoglobin), thrombocytopenia, neurologic symptoms, renal dysfunction, and fever. The
fragmented RBCs (schistocytes) result from RBC destruction on fibrin strands in small vessels. Iron deficiency
shows microcytes with no hemolysis markers. Warm AIHA shows spherocytes but not schistocytes. Aplastic
anemia shows pancytopenia without fragmented cells.
Q3. A patient has a prolonged PT and aPTT. A 1:1 mixing study (equal volumes patient plasma +
normal plasma) is performed. The aPTT corrects to within normal range after incubation. This
result is MOST consistent with:
A. Lupus anticoagulant
B. Factor VIII inhibitor
C. Factor VIII deficiency
D. Heparin contamination
CORRECT ANSWER: C
Rationale: Correction of the aPTT with a mixing study indicates the patient's prolonged clotting time was due
to a factor DEFICIENCY (normal plasma supplied the missing factor). Non-correction indicates an INHIBITOR
(e.g., lupus anticoagulant or specific factor inhibitor) that also inhibits the added normal plasma. Factor VIII
inhibitors characteristically show correction immediately but non-correction after 2-hour incubation (time-
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
temperature dependent inhibitor). A simple deficiency shows immediate and sustained correction. Lupus
anticoagulant is a phospholipid-dependent inhibitor that does not correct.
Q4. A 35-year-old African American patient presents with a hemoglobin electrophoresis
showing: HbS 45%, HbA 50%, HbA2 5%, HbF <1%. This pattern is MOST consistent with:
A. Sickle cell disease (HbSS)
B. Sickle cell trait (HbAS)
C. HbSC disease
D. Beta-thalassemia major
CORRECT ANSWER: B
Rationale: Sickle cell trait (HbAS) shows approximately 40-45% HbS and 55-60% HbA with normal HbA2
and HbF. HbSS disease would show ~95-98% HbS with no HbA. HbSC would show approximately 50% HbS
and 50% HbC with no HbA. Beta-thalassemia major would show elevated HbF and HbA2 without HbS.
Q5. A patient's CBC shows: WBC 95,000/mcL with 85% lymphocytes; the lymphocytes appear
small, mature, and monotonous on smear. Smear also shows 'smudge cells.' Flow cytometry
would MOST likely show:
A. CD19+, CD5+, CD23+ B cells
B. CD33+, CD13+ myeloid blasts
C. CD3+, CD8+ T cells
D. CD138+ plasma cells
CORRECT ANSWER: A
Rationale: Chronic lymphocytic leukemia (CLL)—the most common adult leukemia—presents with marked
lymphocytosis, small mature-appearing lymphocytes, smudge cells (fragile cells that smear), and flow
cytometry showing co-expression of B cell markers (CD19, CD20, CD23) with the T cell marker CD5. This
CD5/CD19 co-expression is pathognomonic for CLL/SLL. The other options describe AML (myeloid blasts), T
cell lymphoma, or multiple myeloma.
Q6. Which of the following CBC findings is MOST consistent with vitamin B12 deficiency?
A. MCV 68 fL, MCH 20 pg, hypersegmented neutrophils absent
B. MCV 112 fL, MCH 35 pg, hypersegmented neutrophils present
C. MCV 88 fL, elevated RDW, target cells on smear
D. MCV 75 fL, elevated TIBC, decreased ferritin
CORRECT ANSWER: B
Rationale: Vitamin B12 (and folate) deficiency causes megaloblastic anemia: markedly elevated MCV (>100
fL, often >110), elevated MCH, oval macrocytes on smear, and hypersegmented neutrophils (5-lobed
neutrophils = pathognomonic; >5% with 5 lobes or any with 6+ lobes). MCV 68 is microcytic. MCV 88 with
target cells suggests hemoglobin disorder or liver disease. MCV 75 with elevated TIBC is iron deficiency.
Q7. A bone marrow aspirate shows >20% blasts with Auer rods present. Flow cytometry shows
CD33+, CD13+, MPO+ cells. The MOST likely diagnosis is:
A. Acute lymphoblastic leukemia (ALL)
B. Acute myeloid leukemia (AML)
C. Chronic myeloid leukemia (CML)
D. Myelodysplastic syndrome (MDS)
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
CORRECT ANSWER: B
Rationale: AML is defined by ≥20% myeloid blasts in the bone marrow (WHO criteria). Auer rods (crystallized
lysosomes) are pathognomonic for myeloid leukemias and are NOT seen in ALL. Myeloid markers CD33,
CD13, and MPO (myeloperoxidase) confirm myeloid lineage. ALL blasts are TdT+, CD10+, CD19+ (B-ALL) or
CD3+, CD7+ (T-ALL) and Auer rod negative. CML has <10% blasts. MDS rarely has blasts >10-20%.
Q8. A patient has a platelet count of 22,000/mcL, PT normal, aPTT normal, bleeding time
prolonged. Bone marrow shows normal to increased megakaryocytes. This is MOST consistent
with:
A. Disseminated intravascular coagulation (DIC)
B. Thrombotic thrombocytopenic purpura (TTP)
C. Immune thrombocytopenic purpura (ITP)
D. Aplastic anemia
CORRECT ANSWER: C
Rationale: ITP is an immune-mediated thrombocytopenia where antibodies destroy platelets peripherally.
Bone marrow compensates with increased megakaryocyte production. PT and aPTT are normal (clotting
factors unaffected). DIC shows low platelets but ALSO abnormal PT/aPTT and D-dimer elevation
(consumptive coagulopathy). TTP has MAHA + thrombocytopenia but no PT/aPTT abnormality. Aplastic
anemia shows pancytopenia with reduced marrow cellularity.
Q9. A patient has target cells, Pappenheimer bodies, basophilic stippling, elevated HbA2 (5.5%),
and mild microcytic anemia. Iron studies are normal. This presentation is MOST consistent with:
A. Iron deficiency anemia
B. Beta-thalassemia minor (trait)
C. Alpha-thalassemia trait
D. HbC disease
CORRECT ANSWER: B
Rationale: Beta-thalassemia minor (trait) is characterized by: mild microcytic anemia, target cells, basophilic
stippling, Pappenheimer bodies, and most importantly elevated HbA2 (>3.5%; normal <3.5%). HbA2 elevation
is the hallmark distinguishing beta-thalassemia from iron deficiency (which shows normal or decreased
HbA2). Alpha-thalassemia trait shows normal HbA2. HbC disease shows target cells but different
electrophoresis pattern.
Q10. Which coagulation test result is MOST consistent with von Willebrand disease (vWD) Type
1?
A. Prolonged aPTT, normal PT, normal platelet count, decreased vWF antigen and activity
B. Prolonged PT, normal aPTT, normal platelet count, normal vWF
C. Prolonged PT and aPTT, decreased fibrinogen, elevated D-dimer
D. Normal PT and aPTT, decreased platelet count, positive DAT
CORRECT ANSWER: A
Rationale: Von Willebrand disease Type 1 (most common—quantitative deficiency of vWF) shows: prolonged
aPTT (vWF stabilizes Factor VIII; low vWF = low FVIII = prolonged aPTT), normal PT, normal platelet count,
and decreased vWF antigen and ristocetin cofactor activity. Prolonged PT points to extrinsic pathway or
common pathway (not vWD). PT+aPTT prolongation with low fibrinogen suggests DIC. Low platelet count
with positive DAT suggests immune thrombocytopenia or HDN.
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
ASCP RECALL EXAM
2026–2027 | Updated Study Guide | Verified Edition
100% Accurate & Verified Questions and Answers | ASCP BOC Examination Content Aligned
100 Questions | 7 Clinical Laboratory Science Domains
Section 1: Hematology (Q1–Q20)
Section 2: Clinical Chemistry (Q21–Q40)
Section 3: Microbiology (Q41–Q55)
Section 4: Blood Bank / Immunohematology (Q56–Q70)
Section 5: Immunology and Serology (Q71–Q80)
Section 6: Urinalysis and Body Fluids (Q81–Q90)
Section 7: Laboratory Operations and Quality (Q91–Q100)
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
SECTION 1: Hematology (Q1–Q20)
CBC Parameters | Anemias | WBC Disorders | Platelets | Coagulation |
Hemoglobinopathies | Bone Marrow
Q1. A patient's CBC shows: Hgb 7.2 g/dL, MCV 58 fL, RDW 18% (elevated), serum iron 28
mcg/dL, TIBC 490 mcg/dL, ferritin 6 ng/mL. What is the MOST likely diagnosis?
A. Anemia of chronic disease
B. Iron deficiency anemia
C. Beta-thalassemia trait
D. Sideroblastic anemia
CORRECT ANSWER: B
Rationale: The combination of low hemoglobin, microcytic (low MCV), elevated RDW (high degree of
anisocytosis), low serum iron, elevated TIBC (body seeking iron), and critically low ferritin (depleted iron
stores) is the classic profile of iron deficiency anemia. Anemia of chronic disease shows low iron but also low
TIBC and normal/high ferritin. Beta-thalassemia trait has low/normal RDW and normal iron studies.
Sideroblastic anemia shows elevated serum iron and ringed sideroblasts on bone marrow.
Q2. A peripheral blood smear from a patient with severe hemolytic anemia shows numerous
schistocytes, microspherocytes, and thrombocytopenia. Laboratory values show elevated LDH,
elevated indirect bilirubin, and decreased haptoglobin. This constellation is MOST consistent
with:
A. Iron deficiency anemia
B. Thrombotic thrombocytopenic purpura (TTP)
C. Warm autoimmune hemolytic anemia
D. Aplastic anemia
CORRECT ANSWER: B
Rationale: TTP is characterized by the pentad: microangiopathic hemolytic anemia (schistocytes, elevated
LDH, decreased haptoglobin), thrombocytopenia, neurologic symptoms, renal dysfunction, and fever. The
fragmented RBCs (schistocytes) result from RBC destruction on fibrin strands in small vessels. Iron deficiency
shows microcytes with no hemolysis markers. Warm AIHA shows spherocytes but not schistocytes. Aplastic
anemia shows pancytopenia without fragmented cells.
Q3. A patient has a prolonged PT and aPTT. A 1:1 mixing study (equal volumes patient plasma +
normal plasma) is performed. The aPTT corrects to within normal range after incubation. This
result is MOST consistent with:
A. Lupus anticoagulant
B. Factor VIII inhibitor
C. Factor VIII deficiency
D. Heparin contamination
CORRECT ANSWER: C
Rationale: Correction of the aPTT with a mixing study indicates the patient's prolonged clotting time was due
to a factor DEFICIENCY (normal plasma supplied the missing factor). Non-correction indicates an INHIBITOR
(e.g., lupus anticoagulant or specific factor inhibitor) that also inhibits the added normal plasma. Factor VIII
inhibitors characteristically show correction immediately but non-correction after 2-hour incubation (time-
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
temperature dependent inhibitor). A simple deficiency shows immediate and sustained correction. Lupus
anticoagulant is a phospholipid-dependent inhibitor that does not correct.
Q4. A 35-year-old African American patient presents with a hemoglobin electrophoresis
showing: HbS 45%, HbA 50%, HbA2 5%, HbF <1%. This pattern is MOST consistent with:
A. Sickle cell disease (HbSS)
B. Sickle cell trait (HbAS)
C. HbSC disease
D. Beta-thalassemia major
CORRECT ANSWER: B
Rationale: Sickle cell trait (HbAS) shows approximately 40-45% HbS and 55-60% HbA with normal HbA2
and HbF. HbSS disease would show ~95-98% HbS with no HbA. HbSC would show approximately 50% HbS
and 50% HbC with no HbA. Beta-thalassemia major would show elevated HbF and HbA2 without HbS.
Q5. A patient's CBC shows: WBC 95,000/mcL with 85% lymphocytes; the lymphocytes appear
small, mature, and monotonous on smear. Smear also shows 'smudge cells.' Flow cytometry
would MOST likely show:
A. CD19+, CD5+, CD23+ B cells
B. CD33+, CD13+ myeloid blasts
C. CD3+, CD8+ T cells
D. CD138+ plasma cells
CORRECT ANSWER: A
Rationale: Chronic lymphocytic leukemia (CLL)—the most common adult leukemia—presents with marked
lymphocytosis, small mature-appearing lymphocytes, smudge cells (fragile cells that smear), and flow
cytometry showing co-expression of B cell markers (CD19, CD20, CD23) with the T cell marker CD5. This
CD5/CD19 co-expression is pathognomonic for CLL/SLL. The other options describe AML (myeloid blasts), T
cell lymphoma, or multiple myeloma.
Q6. Which of the following CBC findings is MOST consistent with vitamin B12 deficiency?
A. MCV 68 fL, MCH 20 pg, hypersegmented neutrophils absent
B. MCV 112 fL, MCH 35 pg, hypersegmented neutrophils present
C. MCV 88 fL, elevated RDW, target cells on smear
D. MCV 75 fL, elevated TIBC, decreased ferritin
CORRECT ANSWER: B
Rationale: Vitamin B12 (and folate) deficiency causes megaloblastic anemia: markedly elevated MCV (>100
fL, often >110), elevated MCH, oval macrocytes on smear, and hypersegmented neutrophils (5-lobed
neutrophils = pathognomonic; >5% with 5 lobes or any with 6+ lobes). MCV 68 is microcytic. MCV 88 with
target cells suggests hemoglobin disorder or liver disease. MCV 75 with elevated TIBC is iron deficiency.
Q7. A bone marrow aspirate shows >20% blasts with Auer rods present. Flow cytometry shows
CD33+, CD13+, MPO+ cells. The MOST likely diagnosis is:
A. Acute lymphoblastic leukemia (ALL)
B. Acute myeloid leukemia (AML)
C. Chronic myeloid leukemia (CML)
D. Myelodysplastic syndrome (MDS)
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
, ASCP Recall Exam | 2026–2027 | 100 Verified Questions | Clinical Laboratory Science
CORRECT ANSWER: B
Rationale: AML is defined by ≥20% myeloid blasts in the bone marrow (WHO criteria). Auer rods (crystallized
lysosomes) are pathognomonic for myeloid leukemias and are NOT seen in ALL. Myeloid markers CD33,
CD13, and MPO (myeloperoxidase) confirm myeloid lineage. ALL blasts are TdT+, CD10+, CD19+ (B-ALL) or
CD3+, CD7+ (T-ALL) and Auer rod negative. CML has <10% blasts. MDS rarely has blasts >10-20%.
Q8. A patient has a platelet count of 22,000/mcL, PT normal, aPTT normal, bleeding time
prolonged. Bone marrow shows normal to increased megakaryocytes. This is MOST consistent
with:
A. Disseminated intravascular coagulation (DIC)
B. Thrombotic thrombocytopenic purpura (TTP)
C. Immune thrombocytopenic purpura (ITP)
D. Aplastic anemia
CORRECT ANSWER: C
Rationale: ITP is an immune-mediated thrombocytopenia where antibodies destroy platelets peripherally.
Bone marrow compensates with increased megakaryocyte production. PT and aPTT are normal (clotting
factors unaffected). DIC shows low platelets but ALSO abnormal PT/aPTT and D-dimer elevation
(consumptive coagulopathy). TTP has MAHA + thrombocytopenia but no PT/aPTT abnormality. Aplastic
anemia shows pancytopenia with reduced marrow cellularity.
Q9. A patient has target cells, Pappenheimer bodies, basophilic stippling, elevated HbA2 (5.5%),
and mild microcytic anemia. Iron studies are normal. This presentation is MOST consistent with:
A. Iron deficiency anemia
B. Beta-thalassemia minor (trait)
C. Alpha-thalassemia trait
D. HbC disease
CORRECT ANSWER: B
Rationale: Beta-thalassemia minor (trait) is characterized by: mild microcytic anemia, target cells, basophilic
stippling, Pappenheimer bodies, and most importantly elevated HbA2 (>3.5%; normal <3.5%). HbA2 elevation
is the hallmark distinguishing beta-thalassemia from iron deficiency (which shows normal or decreased
HbA2). Alpha-thalassemia trait shows normal HbA2. HbC disease shows target cells but different
electrophoresis pattern.
Q10. Which coagulation test result is MOST consistent with von Willebrand disease (vWD) Type
1?
A. Prolonged aPTT, normal PT, normal platelet count, decreased vWF antigen and activity
B. Prolonged PT, normal aPTT, normal platelet count, normal vWF
C. Prolonged PT and aPTT, decreased fibrinogen, elevated D-dimer
D. Normal PT and aPTT, decreased platelet count, positive DAT
CORRECT ANSWER: A
Rationale: Von Willebrand disease Type 1 (most common—quantitative deficiency of vWF) shows: prolonged
aPTT (vWF stabilizes Factor VIII; low vWF = low FVIII = prolonged aPTT), normal PT, normal platelet count,
and decreased vWF antigen and ristocetin cofactor activity. Prolonged PT points to extrinsic pathway or
common pathway (not vWD). PT+aPTT prolongation with low fibrinogen suggests DIC. Low platelet count
with positive DAT suggests immune thrombocytopenia or HDN.
Hematology | Chemistry | Microbiology | Blood Bank | Immunology | Urinalysis | Lab Operations
