What is the typical bone marrow finding in myelofibrosis?
Which of the following statements is false regarding hereditary spherocytosis?
Which is not a feature of paroxysmal nocturnal hemoglobinuria?
What is the major fibril protein associated with Primary Amyloidosis?
Which of the following statements about sickle cell anemia is false?
In which condition are Pseudo-Pelger-Huët cells typically seen?
MALT lymphoma is positive for which of the following markers?
Which of the following statements about Polycythemia vera is false?
In which condition is Hemoglobin F typically elevated?
All of the following are features of juvenile CML except which of the following?
Explanation: ***Dry tap (hypocellular)*** - In myelofibrosis, the bone marrow is often **hypocellular** due to fibrosis [1][2], leading to a **dry tap** during aspiration. - The presence of **reticulin** and collagen deposition replaces normal hematopoietic cells [2], resulting in ineffective hematopoiesis. *Thrombocytosis* - Myelofibrosis typically leads to **thrombocytopenia**, not thrombocytosis, due to ineffective megakaryopoiesis and splenic sequestration. - Though elevated platelets can occur, they are generally a **secondary response** to the disease and not a hallmark finding. *Megaloblastic cells* - Megaloblastic changes are associated with **vitamin B12** or **folate deficiencies**, which do not occur in myelofibrosis. - In myelofibrosis, the predominant issue is **marrow fibrosis** [1][2], which does not lead to megaloblastosis. *Microcytic cells* - Microcytic cells are commonly linked to **iron deficiency anemia**, not myelofibrosis. - Myelofibrosis typically results in **variable red cell morphology** [1], but microcytic anemia is not a primary characteristic. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 628-629. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 615-616.
Explanation: ***Decreased MCHC*** - Hereditary spherocytosis typically presents with an **increased MCHC** due to the spherocytes being more concentrated. - MCHC is a measure of the hemoglobin concentration in red blood cells, and in spherocytosis, this value is often elevated rather than decreased. *Defect in ankyrin* - This is a true statement; hereditary spherocytosis is associated with a defect in **ankyrin**, a protein that helps maintain the cell's membrane structure [2]. - Mutations in ankyrin lead to instability of the red blood cell membrane, resulting in spherocyte formation [2]. *Decreased MCV* - In hereditary spherocytosis, MCV is often **normal or slightly increased**, as it reflects the volume of red blood cells, which can be misinterpreted due to the presence of spherocytes. - Spherocytes are smaller cells, which can mistakenly suggest a falsely decreased MCV if not properly interpreted [1]. *Reticulocytosis* - This condition typically presents with **reticulocytosis** as a response to hemolysis, indicating the bone marrow is producing more red blood cells to compensate [1]. - The presence of reticulocytosis is a common finding in hereditary spherocytosis due to increased destruction of spherocytes. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 597-598. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 640-641.
Explanation: ***Increased LAP score*** - In paroxysmal nocturnal hemoglobinuria, the **LAP score** is typically **low** due to ineffective hematopoiesis and not elevated. - The presence of a low LAP score is inconsistent with the features of this condition, making it the correct choice. *Thrombosis* - Paroxysmal nocturnal hemoglobinuria is **associated with a high risk of thrombosis**, particularly in the **venous system** [2]. - This is due to **increased platelet activation** and excessive thrombin generation resulting from hemolysis. *Hemolysis* - **Hemolysis** is a hallmark feature of paroxysmal nocturnal hemoglobinuria, where there is **destruction of red blood cells** [2,3]. - Patients often present with signs of hemolytic anemia including **elevated bilirubin** and **low haptoglobin** levels. *Thrombocytopenia* - **Thrombocytopenia** is a common finding in paroxysmal nocturnal hemoglobinuria due to **expanded consumption** of platelets during episodes of hemolysis. - This can lead to an **increased risk of bleeding** in affected patients. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 601-602. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 650-651.
Explanation: ***AL*** - In Primary Amyloidosis, **AL amyloid** is derived from immunoglobulin light chains produced by **plasma cell dyscrasias** [1]. - This type of amyloidosis is commonly associated with conditions like **multiple myeloma** or monoclonal gammopathy [1]. *Transthyretin* - This protein is associated with **Familial Amyloid Polyneuropathy** and **Senile Systemic Amyloidosis**, not Primary Amyloidosis. - Transthyretin amyloidosis (ATTR) results from **mutations** or **aging**, contributing to different clinical presentations than AL. *AA* - AA amyloidosis is secondary and occurs due to **chronic inflammatory** conditions, such as rheumatoid arthritis or chronic infections. - It is not the main fibril protein in **Primary Amyloidosis**, which is specifically linked to **light chains**. *Procalcitonin* - Procalcitonin is a **biomarker** used primarily for diagnosing bacterial infections, particularly sepsis, and is not involved in amyloidogenesis. - It does not relate to amyloidosis and is not a component of amyloid fibrils. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 266-267.
Explanation: ***Ringed sideroblast*** - **Ringed sideroblasts** are not typically associated with sickle cell anemia; they are indicative of disorders like **sideroblastic anemia**. - In sickle cell anemia, the primary findings include **hemolysis** and ineffective erythropoiesis, not ringed sideroblasts [3]. *Howell jolly bodies* - These bodies are remnants of nuclear material and can be found in individuals with **spleen dysfunction**, which can occur in sickle cell anemia [1]. - They are actually a common finding due to **hyposplenism** or **asplenia** in patients with sickle cell disease [2]. *Sickle cells* - The presence of **sickle-shaped red blood cells** is a hallmark of sickle cell anemia, caused by the mutation in the **beta-globin chain** [3]. - These sickle cells are responsible for the characteristic complications of the disease, such as **vaso-occlusive crises** [1][3]. *Target cells* - Target cells, or **codocytes**, are often seen in disorders like **thalassemia** and liver disease, and can also be present in sickle cell anemia. - They are formed due to an increase in the **surface area to volume ratio** of red blood cells, often secondary to **membrane abnormalities** seen in sickle cell changes [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 644-646. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 570-571. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 598-599.
Explanation: ***Mylodysplastic syndrome*** - Pseudo-Pelger-Huet cells are characteristic and often observed in myelodysplastic syndromes, indicating an ineffective hematopoiesis [1]. - These cells appear as **hyposegmented neutrophils** and are associated with dysplastic changes in the bone marrow [1]. *Hairy cell leukemia* - Typically presents with **hairy cells** in peripheral blood and often involves splenomegaly; pseudo-Pelger-Huet cells are not usual in this condition. - Associated with **PANCYTOPENIA** and reticulin fibrosis, differing from myelodysplastic syndrome. *Hodgkin's lymphoma* - Characterized by the presence of **Reed-Sternberg cells** and typically involves lymphadenopathy. - Peripheral blood findings generally do not include pseudo-Pelger-Huet cells; the focus is on lymphatic tissue. *Multiple myeloma* - Commonly presents with **plasma cells** and related symptoms like bone pain and renal failure, not associated with pseudo-Pelger-Huet cells. - It primarily causes an increase in monoclonal proteins rather than dysplastic changes seen in myelodysplastic syndrome. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 613-614.
Explanation: ***CD20*** - MALT lymphoma is a type of **B-cell non-Hodgkin lymphoma**, and CD20 is a **pan B-cell marker consistently expressed** in MALT lymphomas. - CD20 positivity is **crucial for diagnosis** and is the **primary therapeutic target** for anti-CD20 monoclonal antibody therapy (Rituximab). - In diagnostic practice, **CD20 is the most important B-cell marker** for identifying MALT lymphoma and guiding treatment decisions. *CD19* - CD19 is also a **pan B-cell marker** and is **typically positive in MALT lymphoma** along with CD20. - However, in the context of this question, **CD20 is the preferred answer** because it is the **standard diagnostic marker emphasized in clinical practice** and the **primary therapeutic target**. - Both markers are positive, but CD20 has greater **clinical and therapeutic significance** in MALT lymphoma management. *CD43* - CD43 is primarily a **T-cell and myeloid marker**, but can show **aberrant expression in 40-50% of MALT lymphomas**. - While it may be positive in some cases, it is **not a defining B-cell lineage marker** and is not used as a primary diagnostic criterion for MALT lymphoma. - Its variable expression makes it **less reliable** than consistent B-cell markers like CD20. *CD5* - CD5 is typically associated with **T-cells** and certain B-cell lymphomas, particularly **chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL)** and **mantle cell lymphoma**. - **MALT lymphoma is characteristically CD5-negative**, which is an important feature for **differentiating it from CD5+ B-cell lymphomas**.
Explanation: ***Decrease LAP score*** - In polycythemia vera, the **LAP (leukocyte alkaline phosphatase) score** is typically increased, indicating more mature leukocytes. - A **decrease in LAP score** is not consistent with the disease, making this statement incorrect. *Increased platelets* - Polycythemia vera often results in **thrombocytosis**, characterized by increased platelet counts [1]. - This is a common feature of the disorder, reflecting overproduction of blood cells in the bone marrow. *Leucocytosis* - Patients with polycythemia vera frequently exhibit **leucocytosis**, or increased white blood cell counts, due to hypercellularity of the bone marrow [1]. - This is an important aspect of the disease, often seen alongside increases in red blood cells and platelets. *Increased vit B12* - An elevation in **vitamin B12** levels can occur in polycythemia vera, often due to increased binding proteins. - This is a well-recognized phenomenon associated with the increased cell turnover in this condition. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 626-627.
Explanation: ***Beta-thalassemia*** - In **beta-thalassemia**, there is reduced or absent synthesis of beta-globin chains, leading to an excess of alpha-globin chains. - To compensate, the body markedly increases production of fetal hemoglobin (**HbF**, α2γ2), which can constitute **50-90% of total hemoglobin** in beta-thalassemia major. - This compensatory mechanism helps alleviate the severity of anemia and ineffective erythropoiesis, making elevated HbF a **defining laboratory feature** of beta-thalassemia. *Hereditary spherocytosis* - This condition is characterized by defects in **erythrocyte membrane proteins** (spectrin, ankyrin, band 3), leading to fragile, spherical red blood cells. - While it causes **hemolytic anemia**, it does not involve elevated HbF levels; the defect is structural, not related to globin chain synthesis. *Congenital red cell aplasia* - This condition (e.g., **Diamond-Blackfan anemia**) involves a primary defect in early **erythroid progenitor cells**, leading to severe anemia. - While some patients may have elevated HbF, it is not a consistent or defining feature; the main problem is the lack of adequate red blood cell production, not a compensatory shift in globin synthesis. *Sickle cell disease* - In **sickle cell disease**, there is an abnormal beta-globin chain leading to the production of **hemoglobin S (HbS)**. - While HbF is indeed elevated in most patients (typically **2-15%**, compared to <1% in normal adults), the elevation is **less marked and consistent** compared to beta-thalassemia. - The primary defect is the presence of HbS, and while HbF elevation provides some clinical benefit (it inhibits HbS polymerization), beta-thalassemia remains the condition most characteristically associated with high HbF levels.
Explanation: ***Philadelphia chromosome is positive*** - **Juvenile Chronic Myeloid Leukemia (JCML)**, now known as **Chronic Myelomonocytic Leukemia (CMML)** of childhood, is characterized by the **absence** of the **Philadelphia chromosome (Ph chromosome)**. - The Ph chromosome, a t(9;22)(q34;q11) translocation forming the **BCR-ABL1 fusion gene**, is the hallmark of adult Chronic Myeloid Leukemia (CML), but not JCML. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a common feature in JCML due to ineffective hematopoiesis and bone marrow infiltration. - This contrasts with adult CML, where **thrombocytosis** (high platelet count) is more characteristic of the chronic phase. *Fetal Hb is increased* - An **increased level of fetal hemoglobin (HbF)** is a characteristic laboratory finding in children with JCML. - This elevation is related to the dysregulated hematopoiesis and is a useful diagnostic marker. *Lymphadenopathy* - **Lymphadenopathy** (enlarged lymph nodes) is a frequent clinical manifestation in JCML, reflecting the widespread infiltration of monocytic cells. - This is part of the systemic involvement seen in this aggressive myeloproliferative disorder.
Anemias: Classification and Approach
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Hemolytic Anemias
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Myeloproliferative Neoplasms
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Myelodysplastic Syndromes
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Acute Leukemias
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Chronic Leukemias
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Lymphomas and Lymphoid Neoplasms
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Plasma Cell Disorders
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Thrombotic Disorders
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