A blood smear shows RBCs with 'bite cells'. Which additional finding would best support G6PD deficiency?
A bone marrow aspirate shows blast cells with multiple Auer rods arranged in bundles ('faggot cells'). Which molecular finding would confirm acute promyelocytic leukemia?
Which of the following has Autosomal Recessive inheritance?
A patient has MCV <80, MCH <23. Which type of anaemia shall be classified?
To replenish the inventory, blood banks routinely issue blood packets which are close to the expiry date. Which of the following will be the closest to expiry date, according to the anticoagulant used and the method of storage of the packet:
Which of the following is not expressed in majority of cases of pediatric B-cell acute lymphoblastic leukemia?
t(2,8) is associated with:
Which one of the following blood fractions is stored at -18°C?
In polycythemia vera all are true except
Lead poisoning is characterised by:
Explanation: ***Heinz bodies on supravital stain*** - **Bite cells** form when the spleen removes precipitated hemoglobin (Heinz bodies) from red blood cells, a hallmark of **oxidative stress** often seen in **G6PD deficiency** [1]. - **Heinz bodies** are denatured hemoglobin precipitates visible with **supravital stains** and their presence directly indicates oxidative damage to hemoglobin [1]. *Pappenheimer bodies* - These are **iron-containing granules** (siderosomes) found in red blood cells, typically associated with **sideroblastic anemia** or conditions of impaired iron utilization. - Their presence does not indicate the oxidative hemolysis characteristic of G6PD deficiency. *Cabot rings* - These are **thread-like inclusions** in red blood cells that are remnants of the **mitotic spindle**, often seen in conditions like **megaloblastic anemia** or lead poisoning. - They are not associated with hemoglobin precipitation or oxidative stress. *Howell-Jolly bodies* - These are **nuclear remnants** in red blood cells, indicating either **splenic hypofunction** (e.g., in sickle cell disease, post-splenectomy) or **hyposplenism**. - Their presence points to impaired splenic removal of cellular debris, not oxidative damage to hemoglobin like Heinz bodies. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 642-643.
Explanation: PML-RARA translocation - The presence of Auer rods arranged in bundles forming faggot cells is highly characteristic of acute promyelocytic leukemia (APL) [1]. - APL is genetically defined by the t(15;17) translocation, which creates the PML-RARA fusion gene [1], [2]. BCR-ABL translocation - This translocation, t(9;22), is characteristic of chronic myeloid leukemia (CML) and some cases of acute lymphoblastic leukemia (ALL), not APL [2]. - It does not typically present with the morphologic features of APL, such as faggot cells. AML1-ETO translocation - The t(8;21) translocation results in the AML1-ETO fusion gene and is associated with a specific subtype of acute myeloid leukemia (AML) with maturation, typically M2 [1]. - While Auer rods can be seen, the bundled faggot cells are not characteristic of this subtype [1]. inv(16) mutation - The inv(16)(p13q22) mutation is associated with acute myelomonocytic leukemia (AMML) with eosinophilia (M4Eo) [1]. - This subtype also features a specific morphology with abnormal eosinophils, not the faggot cells seen in APL [1]. **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. 620-621. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 605-607.
Explanation: **Sickle cell anaemia** - This condition is inherited in an **autosomal recessive** pattern [2], meaning an individual must inherit two copies of the defective gene (one from each parent) to manifest the disease [3]. - It is caused by a mutation in the **beta-globin gene** [1], leading to abnormal hemoglobin production and characteristic sickle-shaped red blood cells [1]. *Osteogenesis imperfecta* - This disorder is predominantly inherited in an **autosomal dominant** pattern, meaning only one copy of the mutated gene is sufficient to cause the condition. - It is characterized by **brittle bones** due to defects in type I collagen synthesis. *Hereditary spherocytosis* - The most common and severe forms of hereditary spherocytosis are inherited as an **autosomal dominant** trait, though rarer autosomal recessive forms exist. - It involves defects in red blood cell membrane proteins, leading to **spherocytes** and hemolytic anemia. *von Willebrand Disease Type 1* - This is the most common type of von Willebrand disease and is inherited in an **autosomal dominant** pattern. - It is characterized by a **partial quantitative deficiency** of von Willebrand factor. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 598-599. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 53-54. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 150-151.
Explanation: ***Microcytic hypochromic*** - A **Mean Corpuscular Volume (MCV)** less than **80 fL** indicates **microcytosis** (small red blood cells) [1]. - A **Mean Corpuscular Hemoglobin (MCH)** less than **23 pg** indicates **hypochromia** (pale red blood cells due to reduced hemoglobin content) [1]. *Normocytic normochromic* - This classification refers to red blood cells with **normal MCV (80-100 fL)** and **normal MCH (27-32 pg)**. - Examples include anemia of chronic disease or acute blood loss, which do not fit the given lab values. *Normocytic hypochromic* - While **hypochromia (MCH <23)** is present, the **MCV is less than 80 fL**, which makes it microcytic, not normocytic. - This combination is not a standard classification; hypochromia typically accompanies microcytosis [1]. *Hyperchromic macrocytic* - **Macrocytic anemia** is characterized by an **MCV >100 fL**, which is the opposite of the given MCV of <80. - The term "hyperchromic" is generally not used for anemia classification because red blood cells have a maximal hemoglobin concentration and cannot be truly hyperchromic. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591.
Explanation: ***SAGM, 25 days with irradiation*** - **SAGM** (Saline-Adenine-Glucose-Mannitol) is an additive solution that extends the storage life of red blood cells significantly. - While SAGM usually allows for storage up to **42 days**, if the blood is **irradiated**, the shelf life is reduced to **28 days from collection or 14 days from irradiation, whichever is sooner**. Given the options, 25 days with irradiation falls within this reduced shelf life, making it the closest to expiry among the provided choices (implying the Irradiation was done earlier). *ACD, 14 days* - **ACD** (Acid Citrate Dextrose) is an older anticoagulant primarily used for apheresis products. - Red blood cells collected with ACD typically have a maximum storage duration of **21 days**. While 14 days is within this, other anticoagulant-additive combinations offer longer storage, and this option is not the closest to expiry when considering the maximum allowed. *CPDA, 27 days* - **CPDA** (Citrate Phosphate Dextrose Adenine) provides a standard shelf life of **35 days** for red blood cells. - While 27 days represents blood that has been stored for a significant period, it still has 8 more days until its maximum expiry, making it less "close to expiry" than the irradiated SAGM option which would expire sooner. *SAGM, 35 days* - **SAGM** (Saline-Adenine-Glucose-Mannitol) allows for the storage of red blood cells for up to **42 days** from collection. - At 35 days, a unit stored in SAGM still has 7 days until its maximum expiry date (if not irradiated), making it less "close to expiry" than a unit that had been irradiated.
Explanation: ***CD7*** - **CD7** is a **T-cell associated antigen** and is typically **not expressed** on B-cell acute lymphoblastic leukemia (ALL) cells [1]. - Its presence would suggest a **T-cell ALL** or an atypical mixed phenotype leukemia, rather than a B-cell ALL. *Terminal deoxynucleotidyl transferase (TdT)* - **TdT** is a **nuclear enzyme** that adds random nucleotides to V(D)J gene segments during lymphoid development and is a **marker of immaturity** in both B and T cell lymphoblasts [2]. - It is **expressed in the majority of B-cell ALL cases** and is crucial for diagnosis. *CD19* - **CD19** is an **early and pan-B-cell marker** that is consistently expressed by B-cell lymphoblasts throughout their development [1]. - It is a **key diagnostic marker** for B-cell ALL. *CD10* - **CD10**, also known as **common acute lymphoblastic leukemia antigen (CALLA)**, is expressed in most progenitor and pre-B ALLs [1]. - Its presence is an important marker used in the immunophenotyping of **B-cell ALL**, particularly the common ALL subtype [2]. **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, p. 598. [2] 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. 599-600.
Explanation: ***B cell ALL*** - The translocation **t(2;8)(p11;q24)** is a **variant cytogenetic abnormality** specifically associated with **Burkitt lymphoma/leukemia**, a highly aggressive form of mature B-cell neoplasm, which can present as B-cell ALL. [1] - This variant translocation (occurring in ~15% of Burkitt lymphoma cases) leads to the **dysregulation of the MYC oncogene** on chromosome 8q24 due to its juxtaposition with the **kappa (κ) immunoglobulin light chain gene (IGK)** on chromosome 2p11. [1] - The most common translocation in Burkitt lymphoma is **t(8;14)(q24;q32)** involving MYC and the immunoglobulin heavy chain gene IGH (~80% of cases), while **t(8;22)** involving the lambda light chain occurs in ~5% of cases. [1] *T cell ALL* - T-cell ALL is primarily associated with translocations involving **T-cell receptor genes (e.g., TCRα/δ on 14q11, TCRβ on 7q34)** and various oncogenes like *TAL1*, *LMO1*, *LMO2*, *HOXA*, and *NKX2-5*. - It does not typically involve the **t(2;8) translocation**. *CML* - **Chronic Myeloid Leukemia (CML)** is classically defined by the presence of the **Philadelphia chromosome**, an acquired reciprocal translocation **t(9;22)(q34;q11)**. - This translocation results in the formation of the **BCR-ABL1 fusion gene**, which encodes a constitutively active tyrosine kinase. *CLL* - **Chronic Lymphocytic Leukemia (CLL)** is most frequently associated with cytogenetic abnormalities such as **deletions of 13q14, 11q22-23 (ATM gene), and 17p13 (TP53 gene)**, and **trisomy 12**. - The **t(2;8) translocation** is not characteristic of CLL. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, pp. 324-325.
Explanation: ***Cryoprecipitate*** - **Cryoprecipitate** contains high concentrations of **Factor VIII**, **von Willebrand factor**, **Factor XIII**, and **fibrinogen**, which are unstable at room temperature [1]. - Storage at **-18°C or colder** is essential to maintain the activity and stability of these coagulation factors for up to one year. *Packed red cells* - **Packed red cells** are typically stored at **2-6°C** for up to 42 days, not frozen, as freezing would damage the red blood cells. - Their primary function is to increase **oxygen-carrying capacity** in patients with anemia or acute blood loss. *Human albumin* - **Human albumin** is a stable protein and is typically stored at **room temperature (2-25°C)**, as freezing is not required to preserve its function. - It is used for **volume expansion** and to maintain **oncotic pressure** in conditions like hypovolemia or hypoalbuminemia. *Platelet concentrate* - **Platelet concentrates** must be stored at **20-24°C** with continuous agitation for up to 5-7 days to maintain their viability and function [2]. - Freezing would irreversibly damage the platelets, making them ineffective for treating **thrombocytopenia** or platelet dysfunction [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 582-583. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 581-582.
Explanation: ***High ESR*** - In **polycythemia vera**, the **increased red blood cell mass** leads to **hyperviscosity** and often a **decreased erythrocyte sedimentation rate (ESR)**, as the red blood cells settle more slowly due to hindrance. - A high ESR would be **atypical** for polycythemia vera and would suggest an underlying inflammatory process or another condition. *Increased leukocyte alkaline phosphatase* - **Leukocyte alkaline phosphatase (LAP) score** is typically **increased** in polycythemia vera, reflecting the **overproduction of mature neutrophils**. - This is a distinguishing feature from disorders like **chronic myeloid leukemia (CML)**, where the LAP score is low [3]. *Thrombocytosis* - **Thrombocytosis** (elevated platelet count) is a common finding in polycythemia vera due to the **panmyelosis** associated with the disease [1], [3]. - The **JAK2V617F mutation**, frequently present in PV, stimulates megakaryocyte production, leading to increased platelets [1]. *Decreased levels of erythropoietin* - In polycythemia vera, red blood cell production is **independent of erythropoietin**, leading to a **suppressed** or **very low erythropoietin level** in response to the high red cell mass [1], [2]. - This differentiates PV from **secondary polycythemia**, where erythropoietin levels are elevated [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 614-615. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 663-664. [3] 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: ***Microcytic anaemia*** - Lead poisoning inhibits enzymes involved in **heme synthesis**, leading to impaired hemoglobin production. [1] - This results in the formation of smaller red blood cells with reduced hemoglobin content, hence **microcytic** (small cell) and often **hypochromic** (pale cell) anemia. *Eosinophilic stippling of WBC* - **Eosinophilic stippling** refers to the presence of fine, reddish-pink granules within eosinophils, which is a normal characteristic of these cells. - **Basophilic stippling** of red blood cells, not eosinophilic stippling of WBCs, is a characteristic finding in lead poisoning due to ribosomal aggregation. *Normochromic normocytic anaemia* - This type of anemia involves red blood cells that are normal in size and hemoglobin content, often seen in conditions like **acute blood loss** or **chronic kidney disease**. - Lead poisoning typically impairs hemoglobin synthesis, leading to **microcytic** and often **hypochromic** red cells. [1] *Hypochromic normocytic anaemia* - **Hypochromic normocytic anemia** means the red blood cells are pale (low hemoglobin) but normal in size. - While lead poisoning can cause hypochromia, it primarily leads to **microcytosis** (small red blood cells) due to the impaired heme synthesis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 418-419.
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