Hematology (anemias, clotting disorders)

Hematology (anemias, clotting disorders) US Medical PG Question 1: A 25-year-old woman is being evaluated due to complaint of fatigue and voiding pink urine. The laboratory results are as follows: Hb 6.7 Red blood cell count 3.0 x 1012/L Leukocyte count 5,000/mm3 Platelets 170 x 109/L Reticulocyte count 6% Hematocrit 32% The physician thinks that the patient is suffering from an acquired mutation in hematopoietic stem cells, which is confirmed by flow cytometry analysis that revealed these cells are CD 55 and CD 59 negative. However, the physician is interested in knowing the corrected reticulocyte count before starting the patient on eculizumab. What value does the physician find after calculating the corrected reticulocyte count?

• A. 3.1%
• B. 0.4%
• C. 0.1%
• D. 0.6%
• E. 4.6% (Correct Answer)

Hematology (anemias, clotting disorders) Explanation: ***4.6%*** - The corrected reticulocyte count accounts for the degree of anemia by adjusting for the patient's hematocrit compared to normal. - **Formula: Corrected Retics% = Observed Retics% × (Patient's Hct / Normal Hct)** - Using normal Hct of 42% for women: 6% × (32/42) = 6% × 0.76 = **4.56% ≈ 4.6%** - This reflects the actual reticulocyte production capacity adjusted for the anemic state. *3.1%* - This value might result from using an incorrect normal hematocrit value in the calculation. - For example, using 6% × (32/60) would give approximately 3.2%, suggesting use of an inappropriately high reference value. *0.4%* - This value likely results from applying the **Reticulocyte Production Index (RPI)** formula, which includes a maturation factor correction: 6% × (32/42) × (1/2.5) = 1.82%, then with further error. - Such a low value from formula misapplication does not represent the standard corrected reticulocyte count requested. *0.1%* - This extremely low value would indicate **severe calculation error** or bone marrow failure, which contradicts the observed 6% reticulocyte count. - In PNH with hemolysis, reticulocyte production is typically increased, making this value implausible. *0.6%* - This incorrect value could result from mathematical errors in applying correction factors or using the wrong hematocrit values in the formula. - The standard corrected reticulocyte formula would not yield this value with the given parameters.

Hematology (anemias, clotting disorders) US Medical PG Question 2: An otherwise healthy 42-year-old man undergoes routine investigations prior to blood donation. His complete blood count is shown: Hemoglobin 9.3 g/dL Mean corpuscular volume (MCV) 71 μm3 Mean corpuscular hemoglobin (MCH) 21 pg/cell White blood cell count 8,200/mm3 Platelet count 317,000/mm3 Iron studies are shown: Serum iron 210 μg/dL Serum ferritin 310 ng/mL Total iron binding capacity (TIBC) 290 μg/dL Transferrin saturation 78% He occasionally drinks alcohol and denies smoking or use of illicit drugs. There is a family history of anemia including his brother and maternal uncle. Examination shows conjunctival pallor, but is otherwise unremarkable. Which of the following is the most likely diagnosis?

• A. Hemochromatosis
• B. Anemia of chronic disease
• C. Acute myeloid leukemia
• D. Sideroblastic anemia (Correct Answer)
• E. Myelodysplastic syndrome

Hematology (anemias, clotting disorders) Explanation: ***Sideroblastic anemia*** - The patient presents with **microcytic anemia** (Hb 9.3 g/dL, MCV 71, MCH 21) and evidence of **iron overload** (serum iron 210, ferritin 310, transferrin saturation 78%). These findings, along with a **family history of anemia affecting males** (brother and maternal uncle), are classic for **hereditary sideroblastic anemia**, typically X-linked. - **Sideroblastic anemia** is characterized by the bone marrow producing ring sideroblasts (erythroblasts with iron-laden mitochondria), leading to ineffective erythropoiesis and iron accumulation. - The hereditary form presents in younger patients with isolated anemia and strong family history, distinguishing it from acquired forms. *Hemochromatosis* - While **hemochromatosis** also presents with iron overload (high serum iron, ferritin, and transferrin saturation), it typically does **not cause microcytic anemia** or any significant anemia. - The primary defect in hemochromatosis is increased iron absorption leading to tissue iron deposition (liver, heart, pancreas), without the erythropoietic dysfunction seen in sideroblastic anemia. *Anemia of chronic disease* - **Anemia of chronic disease (ACD)** typically presents with normal or slightly reduced MCV and MCH, and is characterized by **low serum iron** and **low TIBC**, with normal or elevated ferritin. - In this case, the patient has **elevated serum iron** and **high transferrin saturation (78%)**, making ACD unlikely. *Acute myeloid leukemia* - **Acute myeloid leukemia (AML)** involves the proliferation of immature myeloid cells and usually presents with pancytopenia or symptoms related to bone marrow failure (e.g., fatigue, bleeding, infections). - The blood counts here show **isolated anemia with normal WBC and platelet counts**, and the iron studies are not typical for AML. *Myelodysplastic syndrome* - **Myelodysplastic syndromes (MDS)** are clonal disorders of hematopoietic stem cells, often presenting with cytopenias and dysplastic features in the bone marrow. - While **acquired sideroblastic anemia** is a subtype of MDS (refractory anemia with ring sideroblasts), it typically occurs in **older adults (>60 years)** without a family history. - This patient's **young age (42 years)** and **strong family history** (brother and maternal uncle) point to **hereditary sideroblastic anemia** rather than MDS-associated acquired sideroblastic anemia.

Hematology (anemias, clotting disorders) US Medical PG Question 3: A 10-year-old girl with previously diagnosed sickle cell anemia presents to the emergency room with a low-grade fever, malaise, petechiae on her arms, and a rash on her face. She regularly takes hydroxyurea and receives blood transfusions to treat her condition. Her blood tests show a hemoglobin of 4.0 g/dL, MCV of 87 fl, and 2% reticulocyte count. An attempted bone marrow biopsy was a dry, empty tap. What is the most likely diagnosis?

• A. Reaction to the blood transfusions
• B. Gastrointestinal bleeding
• C. Anemia of chronic disease
• D. Aplastic crisis (Correct Answer)
• E. Sequestration crisis

Hematology (anemias, clotting disorders) Explanation: ***Aplastic crisis*** - The combination of **severe anemia** (hemoglobin 4.0 g/dL), **low reticulocyte count** (2%), and a **dry bone marrow tap** confirms a defect in red blood cell production. - In a patient with **sickle cell anemia**, an aplastic crisis is often triggered by **Parvovirus B19 infection**, which targets erythroid precursors. *Reaction to the blood transfusions* - An acute transfusion reaction would typically present with fever, chills, urticaria, or dyspnea, which are not the predominant symptoms here. - Hemoglobin would likely drop acutely or remain stable, but not necessarily with such a profound reticulocytopenia or bone marrow findings. *Gastrointestinal bleeding* - While GI bleeding can cause severe anemia, it would typically be associated with **microcytic anemia** (decreased MCV if chronic) and **elevated reticulocyte count** as the bone marrow tries to compensate, neither of which are observed. - There is no mention of melena or hematochezia, and the dry bone marrow tap points to a production problem, not blood loss. *Anemia of chronic disease* - This condition typically results in **mild to moderate anemia** with a **normal or slightly reduced MCV** and a **low reticulocyte count**. - However, the hemoglobin level of 4.0 g/dL is too severe for typical anemia of chronic disease, and the dry bone marrow tap is not a characteristic finding. *Sequestration crisis* - A sequestration crisis involves the rapid pooling of blood in the spleen or liver, leading to **acute severe anemia** and often **splenomegaly**. - However, it would be characterized by a **high reticulocyte count** as the bone marrow attempts to compensate for the sudden blood loss, which is contrary to the findings in this case.

Hematology (anemias, clotting disorders) US Medical PG Question 4: A 39-year-old woman presents with progressive weakness, exercise intolerance, and occasional dizziness for the past 3 months. Past medical history is unremarkable. She reports an 18-pack-year smoking history and drinks alcohol rarely. Her vital signs include: temperature 36.6°C (97.8°F), blood pressure 139/82 mm Hg, pulse 98/min. Physical examination is unremarkable. Her laboratory results are significant for the following: Hemoglobin 9.2 g/dL Erythrocyte count 2.1 million/mm3 Mean corpuscular volume (MCV) 88 μm3 Mean corpuscular hemoglobin (MCH) 32 pg/cell Leukocyte count 7,500/mm3 Which of the following is the best next step in the management of this patient’s condition?

• A. Serum ferritin level
• B. Direct antiglobulin test
• C. C-reactive protein (CRP)
• D. Bone marrow biopsy
• E. Reticulocyte count (Correct Answer)

Hematology (anemias, clotting disorders) Explanation: ***Reticulocyte count*** - A **normocytic anemia** (MCV 88) with signs of weakness and exercise intolerance requires evaluation of **red blood cell production**. - A reticulocyte count helps differentiate between **hypoproliferative** (low count) and **hyperproliferative** (high count) anemias, guiding further diagnostic steps. *Serum ferritin level* - While often low in **iron-deficiency anemia**, this patient’s **normocytic MCV** makes iron deficiency less likely as the primary cause without other features. - A normal ferritin doesn't rule out other causes of anemia, and a high ferritin could indicate **anemia of chronic disease**, but further understanding of RBC production is needed first. *Direct antiglobulin test* - This test is used to diagnose **autoimmune hemolytic anemia**, which typically presents with **jaundice**, **splenomegaly**, and elevated **lactate dehydrogenase (LDH)**, none of which are noted here. - While anemia can result from hemolysis, the initial presentation doesn't strongly suggest an immune-mediated destruction process, and determining the bone marrow's response is more immediate. *C-reactive protein (CRP)* - CRP is a marker of **inflammation**, and elevated levels could suggest **anemia of chronic disease**. - However, knowing the **reticulocyte count** will provide more direct information about bone marrow function, which is crucial for characterizing the anemia. *Bone marrow biopsy* - A bone marrow biopsy is an **invasive procedure** typically reserved for complex anemias where initial, less invasive tests have failed to provide a diagnosis or when conditions like **aplastic anemia** or **myelodysplastic syndromes** are strongly suspected. - It is not the appropriate **first diagnostic step** in evaluating an undifferentiated normocytic anemia like this.

Hematology (anemias, clotting disorders) US Medical PG Question 5: A 42-year-old man with a history of tuberculosis presents to your office complaining of fatigue for two months. Serum laboratory studies reveal the following: WBC 7,000 cells/mm^3, Hb 9.0 g/dL, Hct 25%, MCV 88 fL, Platelet 450,000 cells/mm^3, Vitamin B12 500 pg/mL (200-800), and Folic acid 17 ng/mL (2.5-20). Which of the following is the most appropriate next step in the management of anemia in this patient?

• A. Iron studies (Correct Answer)
• B. Bone marrow biopsy
• C. Observation
• D. Colonoscopy
• E. Erythropoietin administration

Hematology (anemias, clotting disorders) Explanation: ***Iron studies*** - The patient has **normocytic anemia** (MCV 88 fL) and a history of **tuberculosis**, which is a chronic inflammatory condition often associated with **anemia of chronic disease (ACD)**. - **Iron studies** are critical to differentiate between **ACD** (typically high ferritin, low transferrin saturation) and iron deficiency anemia, which can coexist. *Bone marrow biopsy* - A **bone marrow biopsy** is an invasive procedure and is typically reserved for cases of unexplained severe anemia, pancytopenia, or suspicion of primary bone marrow disorders that are not suggested by the current findings. - The current blood counts do not indicate an urgent need for bone marrow evaluation, as the **anemia is mild to moderate**, and other cell lines are normal (WBC) or elevated (platelets). *Erythropoietin administration* - **Erythropoietin administration** is used in specific anemias, such as **anemia of chronic kidney disease** or certain types of myelodysplastic syndromes. - It is not the initial step for diagnosing and managing anemia in a patient with a chronic inflammatory condition like tuberculosis without first assessing iron status or ruling out other treatable causes. *Observation* - **Observation** is inappropriate given the patient's symptomatic anemia (fatigue) and the identified abnormalities (Hb 9.0 g/dL). - Anemia warrants investigation to identify its cause and provide appropriate treatment, especially in the context of a chronic illness like tuberculosis. *Colonoscopy* - A **colonoscopy** is indicated if there is suspicion of **gastrointestinal blood loss**, which typically presents with **microcytic anemia** (low MCV) due to chronic iron deficiency. - This patient has **normocytic anemia**, and there are no symptoms suggestive of GI bleeding, making colonoscopy not the most appropriate first step.

Hematology (anemias, clotting disorders) US Medical PG Question 6: A 71-year-old woman is brought to the emergency department following a syncopal episode. Earlier in the day, the patient had multiple bowel movements that filled the toilet bowl with copious amounts of bright red blood. Minutes later, she felt dizzy and lightheaded and collapsed into her daughter's arms. The patient has a medical history of diabetes mellitus and hypertension. Her temperature is 99.0°F (37.2°C), blood pressure is 155/94 mmHg, pulse is 82/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient's exam is notable for fecal occult blood positivity on rectal exam; however, the patient is no longer having bloody bowel movements. The patient's lungs are clear to auscultation and her abdomen is soft and nontender. Labs are ordered as seen below. Hemoglobin: 7.1 g/dL Hematocrit: 25% Leukocyte count: 5,300/mm^3 with normal differential Platelet count: 182,500/mm^3 Two large bore IV's are placed and the patient is given normal saline. What is the best next step in management?

• A. Packed red blood cells
• B. Type and screen (Correct Answer)
• C. Fresh frozen plasma
• D. CT abdomen
• E. Colonoscopy

Hematology (anemias, clotting disorders) Explanation: ***Type and screen*** - The patient has experienced a **significant colonic bleed** with associated **syncopal episode** and a **hemoglobin drop** to 7.1 g/dL. Before administering blood products, **blood typing and cross-matching** must be performed to ensure compatibility. - This step is critical for **patient safety** to prevent transfusion reactions, especially given the likelihood of needing a transfusion soon. - In the **sequence of acute blood loss management**, type and screen must be completed **before** packed red blood cells can be safely administered, making it the immediate next step after initial resuscitation with IV fluids. *Packed red blood cells* - While the patient will likely need **packed red blood cells (PRBCs)** due to severe anemia (Hb 7.1 g/dL) and hemodynamic instability (syncopal episode), PRBCs cannot be administered safely without first performing a **type and screen** to ensure compatibility. - Administering PRBCs before compatibility testing is generally reserved for **life-threatening emergencies** with ongoing massive hemorrhage where there is no time for even an immediate cross-match (in which case O-negative blood would be used). - This patient, while anemic, is currently **hemodynamically stable** (normal BP and pulse), allowing time for proper type and screen. *Fresh frozen plasma* - **Fresh frozen plasma (FFP)** is used to replace clotting factors in patients with **coagulopathies** or significant bleeding, often observed in massive transfusions or liver disease. - This patient's **platelet count is normal** and there is no information to suggest a coagulopathy, thus FFP is not indicated as the immediate next step. *CT abdomen* - A **CT scan of the abdomen** may be useful later to identify the cause of the lower GI bleed, such as diverticulosis or angiodysplasia. - However, the immediate priority is to **stabilize the patient hemodynamically** and address the acute blood loss before pursuing diagnostic imaging. *Colonoscopy* - A **colonoscopy** is the definitive diagnostic and potentially therapeutic procedure for a lower GI bleed. - However, before performing a colonoscopy, the patient must be **hemodynamically stable**, which includes addressing their **anemia** and ensuring adequate blood product availability.

Hematology (anemias, clotting disorders) US Medical PG Question 7: A 4-year-old boy is brought to the physician for the evaluation of fatigue since he returned from visiting family in South Africa one week ago. The day after he returned, he had fever, chills, and diffuse joint pain for 3 days. His symptoms improved with acetaminophen. He was born at term and has been healthy. His immunizations are up-to-date. His temperature is 37.6°C (99.68°F), pulse is 100/min, and blood pressure is 100/60 mm Hg. Examination shows conjunctival pallor. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.8 g/dL Mean corpuscular volume 68 μm3 Red cell distribution width 14% (N = 13%–15%) Hemoglobin A2 6% (N < 3.5%) A peripheral smear shows microcytic, hypochromic erythrocytes, some of which have a darkly stained center and peripheral rim, separated by a pale ring. Which of the following is the most appropriate next step in the management of this patient?

• A. Oral pyridoxine
• B. Iron supplementation
• C. Reassurance (Correct Answer)
• D. Folic acid therapy
• E. Oral succimer

Hematology (anemias, clotting disorders) Explanation: ***Reassurance*** - The patient's presentation with **microcytic anemia**, elevated **Hemoglobin A2 (6%)**, and **target cells** on peripheral smear is highly suggestive of **beta-thalassemia trait** (minor). This genetic condition is more common in individuals with Mediterranean, African, Middle Eastern, or South Asian ancestry. - Beta-thalassemia trait is a **benign condition** that does not typically require specific medical intervention. The mild anemia does not usually cause significant symptoms or complications, and patients can live normal lives without treatment. - The elevated HbA2 is the key diagnostic finding that distinguishes thalassemia trait from iron deficiency anemia. *Oral pyridoxine* - **Pyridoxine (Vitamin B6)** supplementation is indicated for **sideroblastic anemia**, which can also cause microcytic anemia. - However, sideroblastic anemia typically presents with **ring sideroblasts** in the bone marrow and does not have the characteristic elevated HbA2 seen in beta-thalassemia trait. *Iron supplementation* - **Iron deficiency anemia** is a common cause of microcytic hypochromic anemia, but it would present with **low ferritin** and **low or normal HbA2** (not elevated). - In this case, iron supplementation would not be appropriate and could potentially be harmful due to the risk of **iron overload** in thalassemia syndromes, even in the trait form. - The elevated HbA2 and normal RDW help distinguish thalassemia trait from iron deficiency. *Folic acid therapy* - **Folic acid** is primarily used in the management of **macrocytic anemias** or in conditions with high red blood cell turnover, such as **hemolytic anemias** or major thalassemia syndromes requiring chronic transfusions. - It is not indicated for beta-thalassemia trait, which is a microcytic anemia with normal red blood cell turnover and no significant hemolysis. *Oral succimer* - **Succimer** is a chelating agent used to treat **lead poisoning**, which can cause microcytic anemia with basophilic stippling. - There are no clinical or laboratory findings in this patient (e.g., **basophilic stippling**, developmental delays, neurological symptoms, abdominal pain) to suggest lead poisoning.

Hematology (anemias, clotting disorders) US Medical PG Question 8: A 55-year-old man comes to the physician because of progressive daytime sleepiness and exertional dyspnea for the past 6 months. Physical examination shows conjunctival pallor and several subcutaneous purple spots on his legs. His hemoglobin concentration is 8.5 g/dL, leukocyte count is 3,000/mm3, and platelet count is 16,000/mm3. Which of the following laboratory values is most likely to be increased in this patient?

• A. Reticulocyte count
• B. Lactate dehydrogenase concentration
• C. Transferrin concentration
• D. Erythropoietin concentration (Correct Answer)
• E. Haptoglobin concentration

Hematology (anemias, clotting disorders) Explanation: ***Erythropoietin concentration*** - The patient presents with severe **anemia (Hb 8.5 g/dL)**, **leukopenia**, and **thrombocytopenia**, indicating **pancytopenia**. This severe decrease in red blood cells will trigger the kidneys to produce more **erythropoietin** in an attempt to stimulate red blood cell production in the bone marrow. - Given the pancytopenia, the underlying pathology is likely bone marrow failure (e.g., aplastic anemia, myelodysplastic syndrome), which would explain why the bone marrow is not responding effectively to increased erythropoietin. *Reticulocyte count* - A low or inappropriately normal reticulocyte count in the presence of severe anemia would suggest **bone marrow suppression** or ineffective erythropoiesis, which is consistent with the pancytopenia observed. - An **increased reticulocyte count** would typically be seen in hemolytic anemia or acute blood loss, where the bone marrow is hyperactive in response to RBC destruction or loss. *Lactate dehydrogenase concentration* - **Elevated LDH** is a marker of **cellular damage** or high cell turnover, commonly seen in hemolytic anemia or certain hematologic malignancies. - While it could be elevated in some conditions causing pancytopenia, it's not the most direct or specific compensatory response to chronic anemia as erythropoietin. *Transferrin concentration* - **Transferrin** levels usually **increase** in **iron deficiency anemia** as the body attempts to maximize iron absorption and transport. - While anemia is present, the broad pancytopenia suggests a bone marrow problem rather than a primary iron deficiency, and increased transferrin isn't a direct compensatory mechanism for severe pancytopenia. *Haptoglobin concentration* - **Haptoglobin levels decrease** in conditions involving **intravascular hemolysis**, as haptoglobin binds to free hemoglobin and is then cleared from circulation. - There is no evidence in the clinical picture to suggest hemolysis as the primary cause of anemia; the pancytopenia points to bone marrow pathology.

Hematology (anemias, clotting disorders) US Medical PG Question 9: A 68-year-old woman comes to the physician because of increasing heartburn for the last few months. During this period, she has taken ranitidine several times a day without relief and has lost 10 kg (22 lbs). She has retrosternal pressure and burning with every meal. She has had heartburn for several years and took ranitidine as needed. She has hypertension. She has smoked one pack of cigarettes daily for the last 40 years and drinks one glass of wine occasionally. Other current medications include amlodipine and hydrochlorothiazide. She appears pale. Her height is 163 cm (5 ft 4 in), her weight is 75 kg (165 lbs), BMI is 27.5 kg/m2. Her temperature is 37.2°C (98.96°F), pulse is 78/min, and blood pressure is 135/80 mm Hg. Cardiovascular examination shows no abnormalities. Abdominal examination shows mild tenderness to palpation in the epigastric region. Bowel sounds are normal. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.2 g/dL Mean corpuscular volume 78 μm Mean corpuscular hemoglobin 23 pg/cell Leukocyte count 9,500/mm3 Platelet count 330,000/mm3 Serum Na+ 137 mEq/L K+ 3.8 mEq/L Cl- 100 mEq/L HCO3- 25 mEq/L Creatinine 1.2 mg/dL Lactate dehydrogenase 260 U/L Alanine aminotransferase 18 U/L Aspartate aminotransferase 15 U/L Lipase (N < 280 U/L) 40 U/L Troponin I (N < 0.1 ng/mL) 0.029 ng/mL An ECG shows normal sinus rhythm without ST-T changes. Which of the following is the most appropriate next step in the management of this patient?

• A. 24-hour esophageal pH monitoring
• B. Esophagogastroduodenoscopy (Correct Answer)
• C. Barium swallow
• D. Trial of proton-pump inhibitor
• E. Esophageal manometry

Hematology (anemias, clotting disorders) Explanation: ***Esophagogastroduodenoscopy*** - This patient presents with **alarm symptoms** (weight loss, iron deficiency anemia, persistent heartburn unresponsive to ranitidine) that warrant an immediate investigation for underlying malignancy or severe mucosal damage. - **EGD directly visualizes the esophagus, stomach, and duodenum**, allowing for biopsies of suspicious lesions, which is crucial given her risk factors (smoking, chronic GERD, age). *24-hour esophageal pH monitoring* - This test is primarily used to **diagnose GERD** in patients with typical symptoms but normal endoscopy, or to guide treatment for refractory GERD. - It is not the appropriate first step here because the patient has alarm symptoms, which necessitate direct visualization and biopsy to rule out serious pathology. *Barium swallow* - A barium swallow can identify **structural abnormalities** such as strictures, diverticula, or large masses but has limited utility for detecting subtle mucosal changes or early malignancy. - It does not allow for **biopsy**, which is essential for definitive diagnosis in a patient with alarm symptoms. *Trial of proton-pump inhibitor* - A trial of PPIs is appropriate for patients with **typical GERD symptoms** without alarm features, as a diagnostic and therapeutic intervention. - However, this patient has already tried ranitidine (an H2 blocker) without relief and exhibits multiple **alarm symptoms**, making empirical treatment insufficient and potentially dangerous by delaying diagnosis. *Esophageal manometry* - Esophageal manometry assesses **esophageal motility** and sphincter function, useful for diagnosing motility disorders like achalasia or diffuse esophageal spasm. - It is indicated if a motility disorder is suspected, usually *after* ruling out structural causes with EGD, and does not address the immediate concern of underlying malignancy or severe damage raised by the patient's alarm symptoms.

Hematology (anemias, clotting disorders) US Medical PG Question 10: A 72-year-old woman comes to the physician because of a 1-month history of progressive fatigue and shortness of breath. Physical examination shows generalized pallor. Laboratory studies show: Hemoglobin 5.8 g/dL Hematocrit 17% Mean corpuscular volume 86 μm3 Leukocyte count 6,200/mm3 with a normal differential Platelet count 240,000/mm3 A bone marrow aspirate shows an absence of erythroid precursor cells. This patient’s condition is most likely associated with which of the following?

• A. Cold agglutinins
• B. Thymic tumor (Correct Answer)
• C. HbF persistence
• D. Parvovirus B19 infection
• E. Lead poisoning

Hematology (anemias, clotting disorders) Explanation: ***Thymic tumor*** - The patient's **normocytic anemia** (Hb 5.8 g/dL, Hct 17%, MCV 86 μm3) and the **absence of erythroid precursor cells** in the bone marrow aspirate are characteristic findings of **pure red cell aplasia (PRCA)**. - **Pure red cell aplasia (PRCA)** in adults is frequently associated with an underlying **thymoma**, with up to 50% of adult PRCA cases linked to this condition. *Cold agglutinins* - Cold agglutinins are characteristic of **cold agglutinin disease**, an **autoimmune hemolytic anemia**. - This condition typically presents with signs of **hemolysis** (e.g., elevated reticulocytes, bilirubin, LDH) and would not show an **absence of erythroid precursor cells** in the bone marrow. *HbF persistence* - **Hereditary persistence of fetal hemoglobin (HPFH)** is a benign condition where **HbF** production continues into adulthood. - It is not associated with anemia or bone marrow aplasia and usually results in normal hematological parameters, except for elevated HbF. *Parvovirus B19 infection* - **Parvovirus B19** can cause transient **aplastic crisis** by infecting and destroying erythroid precursors. - While it causes PRCA-like features, it is typically an acute self-limiting condition, particularly in immunocompetent individuals, and is less likely to be an ongoing chronic cause in a 72-year-old without other risk factors for chronic infection or immunodeficiency. *Lead poisoning* - **Lead poisoning** typically causes a **microcytic hypochromic anemia** with **basophilic stippling** on peripheral blood smear. - It primarily interferes with **heme synthesis** and would not cause a complete absence of erythroid precursor cells in the bone marrow.

Hematology (anemias, clotting disorders) Flashcard 1 of 10

Question: Anemia of chronic disease is characterized by _____ TIBC

Answer: decreased

Hematology (anemias, clotting disorders) Flashcard 2 of 10

Question: What type of anemia is caused by TTP, HUS, DIC, and HELLP? _____

Answer: Microangiopathic hemolytic anemia

Hematology (anemias, clotting disorders) Flashcard 3 of 10

Question: Disorders of primary hemostasis present with symptoms of skin bleeding, such as easy _____

Answer: bruising

Hematology (anemias, clotting disorders) Flashcard 4 of 10

Question: Disorders of secondary hemostasis typically present with _____ bleeding (location)

Answer: deep tissue

Hematology (anemias, clotting disorders) Flashcard 5 of 10

Question: Anemia may present with _____, especially with pre-existing coronary artery disease

Answer: angina

Hematology (anemias, clotting disorders) Flashcard 6 of 10

Question: Quantitative disorders of primary hemostasis present with symptoms of skin bleeding, such as _____ (1-2 mm)

Answer: petechiae

Hematology (anemias, clotting disorders) Flashcard 7 of 10

Question: _____ are used for treatment and long-term prevention of DVT

Answer: Oral anticoagulants (e.g. warfarin)

Hematology (anemias, clotting disorders) Flashcard 8 of 10

Question: priapism

Answer: spinal trauma, sickle cell disease, medications

Extra Information: painful, sustained erection not associated with sexual desire or stimulation

Hematology (anemias, clotting disorders) Flashcard 9 of 10

Question: hemorrhagic stroke

Answer:

Extra Information: HTN, anticoagulation, neoplasia, recent ischemic stroke

Hematology (anemias, clotting disorders) Flashcard 10 of 10

Question: hereditary hemorrhagic telangectasia (Osler-Weber-Rendu syndrome)

Answer:

Extra Information: telangectasia, recurrent epistaxis, skin discolorations, arteriovenous malformations (AVMs)AD