Hematopathology

Hematopathology Indian Medical PG Question 1: Pernicious anemia is associated with which of the following pathologies?

• A. Gastric pathology (Correct Answer)
• B. Renal pathology
• C. Esophageal pathology
• D. Oral pathology

Hematopathology Explanation: **Explanation:** **Pernicious Anemia** is a specific form of megaloblastic anemia caused by an autoimmune destruction of the gastric mucosa [1]. The core pathology is **Autoimmune Metaplastic Atrophic Gastritis (Type A Gastritis)** [3]. 1. **Why Gastric Pathology is Correct:** The disease is characterized by the immune system attacking **gastric parietal cells** (found in the body and fundus of the stomach) and **Intrinsic Factor (IF)** [1], [3]. The loss of parietal cells leads to **achlorhydria** (lack of HCl) and a failure to secrete Intrinsic Factor [1]. Since IF is essential for the absorption of Vitamin B12 in the terminal ileum, its absence leads to Vitamin B12 deficiency, resulting in ineffective erythropoiesis and megaloblastic anemia [1]. 2. **Why Other Options are Incorrect:** * **Renal Pathology:** While B12 is excreted by the kidneys, renal failure does not cause pernicious anemia. * **Esophageal Pathology:** Though patients may have dysphagia (Plummer-Vinson is associated with Iron deficiency, not B12), the primary site of pathology is the stomach. * **Oral Pathology:** Patients often present with **Glossitis** (Beefy red tongue), but this is a *clinical manifestation* of the deficiency, not the underlying *pathological cause* of the disease [4]. **High-Yield Clinical Pearls for NEET-PG:** * **Antibodies:** Anti-parietal cell antibodies (more sensitive) and Anti-intrinsic factor antibodies (more specific) [1], [2]. * **Gastric Morphology:** Characterized by diffuse mucosal atrophy, loss of rugal folds, and **intestinal metaplasia** (replacement of gastric epithelium with goblet cells) [1]. * **Malignancy Risk:** Patients have a 3x increased risk of **Gastric Adenocarcinoma** and Gastric Carcinoid tumors [3]. * **Schilling Test:** Historically used to diagnose B12 malabsorption (now largely replaced by serology). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 592-593. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 655-656. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 771-772. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 772-773.

Hematopathology Indian Medical PG Question 2: A 53-year-old male presents with an enlarged supraclavicular lymph node. Examination reveals enlargement of the Waldeyer ring of oropharyngeal lymphoid tissue. There is no hepatosplenomegaly. Lymph node biopsy reveals replacement by a monomorphous population of large lymphoid cells with enlarged nuclei and prominent nucleoli. The CBC is normal except for mild anemia. Immunohistochemical staining and flow cytometry of the node reveals that most lymphoid cells are CD19+, CD10-, CD3-, CD15-, and TdT negative. What is the most likely diagnosis?

• A. Chronic lymphadenitis
• B. Diffuse large B-cell lymphoma (Correct Answer)
• C. Hodgkin disease
• D. Lymphoblastic lymphoma

Hematopathology Explanation: ### **Explanation** **1. Why Diffuse Large B-cell Lymphoma (DLBCL) is Correct:** The clinical and pathological findings are classic for DLBCL, the most common type of Non-Hodgkin Lymphoma (NHL) [1]. * **Morphology:** The biopsy shows a "monomorphous population of large lymphoid cells" with prominent nucleoli, which is the hallmark of DLBCL [3]. * **Immunophenotype:** The cells are **CD19+** (confirming B-cell lineage) and **TdT negative** (ruling out immature/blastic cells). * **Clinical Presentation:** Involvement of the **Waldeyer ring** and extranodal sites is highly characteristic of DLBCL [3]. It typically presents as a rapidly enlarging symptomatic mass [3]. **2. Why Other Options are Incorrect:** * **Chronic Lymphadenitis:** This would show a pleomorphic (mixed) population of cells (lymphocytes, histiocytes, plasma cells) and preserved lymph node architecture, not a monomorphous large-cell infiltrate. * **Hodgkin Disease:** Characterized by **Reed-Sternberg (RS) cells** in a reactive background [5]. RS cells are typically **CD15+ and CD30+**, but **CD19 negative**. The presentation here lacks the characteristic "bimodal" age distribution or contiguous spread. * **Lymphoblastic Lymphoma:** These are immature cells (precursor T or B cells). They would be **TdT positive** (a marker of immaturity) and typically occur in children or adolescents, often presenting with a mediastinal mass (T-cell type) [4]. **3. NEET-PG High-Yield Pearls:** * **DLBCL** is the most common NHL in adults [2]. * **Waldeyer Ring Involvement:** If mentioned in a lymphoma case, think of DLBCL or Mantle Cell Lymphoma [3]. * **Immunophenotype:** Always check **TdT**. TdT(+) = Lymphoblastic; TdT(-) = Mature Lymphoma [4]. * **BCL-6** is the most common genetic alteration in DLBCL (30% of cases) [2]. * **Treatment:** The standard of care is the **R-CHOP** regimen (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 563-564. [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, p. 604. [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. 604-605. [4] 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. 606. [5] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 559-560.

Hematopathology Indian Medical PG Question 3: The nucleotide triplet CTC in the sixth position of the beta-globin chain in DNA forms the complementary nucleotide on mRNA that codes for glutamic acid. A point mutation on the beta-globin chain resulting in the nucleotide triplet CAC forms a complementary nucleotide on mRNA that codes for valine. In sickle cell anemia, what is the expected complementary nucleotide triplet on mRNA, read 5' to 3'?

• A. GAG
• B. CTC
• C. GTG
• D. GUG (Correct Answer)

Hematopathology Explanation: The core concept in this question is the molecular pathology of **Sickle Cell Anemia (HbS)** and the process of **transcription**. 1. **Why GUG is correct:** In a normal beta-globin chain, the DNA triplet is **CTC**. During transcription, this acts as a template to form the mRNA codon **GAG**, which codes for **Glutamic acid**. [1] In Sickle Cell Anemia, a point mutation (missense mutation) occurs where Adenine replaces Thymine in the DNA (**CTC → CAC**). When the mutant DNA triplet **CAC** is transcribed into mRNA, the complementary base pairing (C-G, A-U) results in the codon **GUG**. This codon translates to **Valine** at the 6th position of the beta-globin chain. [1], [2] 2. **Analysis of Incorrect Options:** * **A. GAG:** This is the normal mRNA codon for Glutamic acid. Its presence indicates a healthy beta-globin chain. [1] * **B. CTC:** This is the original DNA triplet, not the mRNA codon. mRNA contains Uracil (U) instead of Thymine (T). * **C. GTG:** This represents the DNA sequence of the coding strand (non-template) in the mutation. mRNA cannot contain Thymine (T). **High-Yield Clinical Pearls for NEET-PG:** * **Mutation Type:** Non-conservative missense mutation (Point mutation). [2] * **Substitution:** Glutamic acid (polar/hydrophilic) is replaced by Valine (non-polar/hydrophobic). [1] * **Pathophysiology:** The hydrophobic valine creates a "sticky patch," leading to hemoglobin polymerization under deoxygenated conditions (T-state), causing the characteristic "sickling." [1], [2] * **Electrophoresis:** On alkaline electrophoresis, HbS moves slower than HbA toward the anode because Valine is neutral, whereas Glutamic acid is negatively charged. **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] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 652-654.

Hematopathology Indian Medical PG Question 4: Purpura fulminans is seen in?

• A. Protein C deficiency (Correct Answer)
• B. Protein S deficiency
• C. AT III deficiency
• D. Factor 5 Leiden mutation

Hematopathology Explanation: **Explanation:** **Purpura Fulminans (PF)** is a life-threatening syndrome characterized by sudden, progressive cutaneous hemorrhage and necrosis due to microvascular thrombosis and disseminated intravascular coagulation (DIC). [1] 1. **Why Protein C deficiency is correct:** Protein C is a vitamin K-dependent natural anticoagulant that inactivates Factors Va and VIIIa. In **neonatal homozygous Protein C deficiency**, there is a total absence of this "brake" on the coagulation cascade. This leads to massive, widespread microvascular thrombosis shortly after birth, manifesting as Purpura Fulminans. It can also occur in adults during the initiation of Warfarin therapy (Warfarin-induced skin necrosis) because Protein C has a shorter half-life than other clotting factors, creating a transient hypercoagulable state. 2. **Why the other options are incorrect:** * **Protein S deficiency:** While Protein S is a cofactor for Protein C and its deficiency causes a hypercoagulable state (venous thromboembolism), it is much less commonly associated with the classic presentation of neonatal Purpura Fulminans compared to Protein C. * **Antithrombin III (AT III) deficiency:** This typically presents as heparin resistance and venous thromboembolism (DVT/PE) rather than acute cutaneous necrosis or Purpura Fulminans. * **Factor V Leiden:** This is the most common inherited cause of thrombophilia. It involves a mutation that makes Factor V resistant to inactivation by Protein C. While it increases the risk of DVT, it does not typically cause Purpura Fulminans. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of PF:** Tissue necrosis, DIC, and small vessel thrombosis. [1] * **Warfarin-induced skin necrosis:** Always remember this is due to a transient Protein C deficiency. * **Management:** Acute PF is treated with Protein C concentrate or Fresh Frozen Plasma (FFP). * **Differential:** Purpura Fulminans is also a hallmark of **Meningococcemia** (due to acquired Protein C consumption). [1] **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 672-673.

Hematopathology Indian Medical PG Question 5: What is the cause of alpha thalassemia?

• A. Deletion of alpha genes (Correct Answer)
• B. Deletion of beta genes
• C. Excess of alpha genes
• D. Single amino acid substitution in alpha chain

Hematopathology Explanation: **Explanation:** **1. Why Option A is Correct:** Alpha thalassemia is primarily caused by the **deletion** of one or more of the four alpha-globin genes located on **chromosome 16** [1]. Unlike beta thalassemia, which is usually caused by point mutations, alpha thalassemia results from unequal crossing over during meiosis, leading to the physical loss of gene loci. The severity of the disease depends on the number of genes deleted: * **1 gene deleted:** Silent carrier [1]. * **2 genes deleted:** Alpha-thalassemia trait (mild microcytic anemia) [1]. * **3 genes deleted:** Hemoglobin H (HbH) disease (excess beta chains form tetramers, $\beta_4$) [1], [2]. * **4 genes deleted:** Hydrops Fetalis (Hb Barts, $\gamma_4$; incompatible with life) [1]. **2. Why Other Options are Incorrect:** * **Option B:** Deletion of beta genes is rare; Beta thalassemia is typically caused by **point mutations** in the promoter or splicing sites of the beta-globin gene on chromosome 11 [1]. * **Option C:** Excess alpha genes do not cause thalassemia; however, co-inheritance of extra alpha genes can worsen the clinical severity of beta thalassemia by increasing the globin chain imbalance [3]. * **Option D:** Single amino acid substitutions characterize **Hemoglobinopathies** (e.g., Sickle Cell Anemia, where valine replaces glutamic acid), not the quantitative reduction seen in thalassemia. **3. NEET-PG High-Yield Pearls:** * **Genetics:** Alpha genes are on Chromosome 16; Beta genes are on Chromosome 11. * **Hb Barts:** High affinity for $O_2$, does not deliver it to tissues, leading to intrauterine hypoxia. * **Diagnosis:** Hb electrophoresis is normal in alpha-thal trait; diagnosis often requires genetic testing (PCR) [2]. * **Blood Smear:** Look for "Golf ball cells" (HbH inclusions) when stained with Brilliant Cresyl Blue [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. 646-650. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 600-601. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 647-648.

Hematopathology Flashcard 1 of 5

Question: Which of the following is a discrete tumor mass arising from lymph nodes? _____

Answer: Lymphoma

Hematopathology Flashcard 2 of 5

Question: What form of non-Hodgkin lymphoma is seen in the image below? _____

Answer: Follicular lymphoma

Hematopathology Flashcard 3 of 5

Question: What type of cell is represented in the image below? _____

Answer: Plasma cell

Hematopathology Flashcard 4 of 5

Question: The given peripheral smear shows abnormal _____ cells with fine hair-like cytoplasmic projections characteristic of hairy cell leukemia.

Answer: B

Hematopathology Flashcard 5 of 5

Question: Tumor cells with multilobulated nuclei (“cloverleaf” or “flower” cells) is characteristic of _____

Answer: Adult T-Cell Leukemia/Lymphoma