What is the most common type of non-Hodgkin's lymphoma found in the orbit?
An intensive care patient develops sepsis. His blood pressure drops to 60/15 mmHg, and he starts to bleed from venipuncture sites. Disseminated intravascular coagulation is suspected. Which of the following sets of stat laboratory values would confirm the likely diagnosis?
Which of the following immunophenotypic features is characteristic of mantle cell lymphoma?
All of the following are features of juvenile chronic myeloid leukemia except one.
Which parameter is primarily used to diagnose macrocytosis in a complete blood count (CBC)?
A 22-year-old woman presents with painless cervical lymphadenopathy, night sweats, and generalized pruritus. An enlarged cervical lymph node is removed for diagnosis, which shows broad bands of fibrosis on cut surface and histologically contains a mixture of cells, including lymphocytes, histiocytes, eosinophils, plasma cells, and scattered large cells with prominent nucleoli. Which of the following is the most likely condition?
Flow cytometry is best used in the measurement of:
Dohle bodies are characteristically seen in which hereditary condition?
Myeloid sarcoma, which is a tumor mass consisting of myeloid blasts occurring at anatomic sites other than the bone marrow, is often characterized by chromosome aberrations. Which of the following is NOT typically associated with myeloid sarcoma?
Which of the following is the most common myeloproliferative disorder?
Explanation: ***B-cell*** - The most common type of non-Hodgkin's lymphoma in the orbit is **B-cell lymphoma**, which typically presents as a **painless mass** [1]. - **B-cell lymphomas** are more frequently associated with systemic lymphoproliferative disorders and have a higher incidence in this region. *NK-cell* - NK-cell lymphomas are rare compared to B-cell and usually present with more aggressive features. - They are less common in the orbit and are often associated with other systemic diseases like **HIV**. *Plasma cell* - Plasma cell neoplasms, such as **multiple myeloma**, are more related to bone marrow involvement rather than orbit-specific lymphomas. - These do not typically arise in the orbit and are less frequently classified under non-Hodgkin's lymphomas. *T-cell* - T-cell lymphomas are less prevalent compared to B-cell lymphomas and have different clinical presentations. - They can be aggressive and may occur in the orbit, but not as commonly as B-cell types. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Eye, pp. 1341-1342.
Explanation: ***Elevated PT, elevated PTT, decreased platelets*** - In **disseminated intravascular coagulation (DIC)**, widespread activation of the **coagulation cascade** consumes clotting factors and platelets, leading to prolonged **prothrombin time (PT)** and **partial thromboplastin time (PTT)**, and a **decreased platelet count** [1]. - Additional laboratory findings in DIC include **elevated D-dimer** (from fibrin degradation) and **decreased fibrinogen** (consumption of clotting factors) [1], [2]. - **Sepsis** is a common trigger for DIC, and the patient's symptoms of **hypotension** (60/15 mmHg) and **bleeding from venipuncture sites** are classic clinical manifestations of DIC [1], [3]. *Decreased PT, elevated PTT, decreased platelets* - A **decreased PT** indicates rapid clotting via the extrinsic pathway, which is not characteristic of DIC. - While **elevated PTT** and **decreased platelets** are consistent with DIC, the overall profile is mismatched. *Decreased PT, elevated PTT, elevated platelets* - A **decreased PT** is inconsistent with DIC, as clotting factor consumption prolongs PT. - An **elevated platelet count** would not be seen in DIC, where platelets are consumed and typically drop. *Decreased PT, decreased PTT, decreased platelets* - **Decreased PT** and **decreased PTT** suggest a hypercoagulable state with accelerated clotting factor activity, which is not the primary feature of DIC. - While **decreased platelets** are consistent, the overall pattern points away from DIC. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 625-626. [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. 151-152. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 671-672.
Explanation: ***CD 5+, CD 23-*** - Mantle cell carcinoma is characterized by **CD5 positivity** and **CD23 negativity**, helping differentiate it from other B-cell neoplasms [1][2]. - This immunophenotype is significant in identifying the **unique biological behavior** of mantle cell lymphoma [2]. *CD 5+, CD 10+* - CD10 positivity is more commonly associated with **follicular lymphoma** or **Burkitt lymphoma**, not mantle cell carcinoma. - Therefore, this oes not accurately reflect the immunophenotypic profile required for a diagnosis. *CD 5+, CD 23+* - CD23 positivity typically indicates **chronic lymphocytic leukemia (CLL)**, which contrasts with the profile seen in mantle cell carcinoma [1]. - This means that mantle cell carcinoma will not be identified with both CD5 and CD23 positivity together. *CD 5+, CD 25-* - CD25 is often expressed in conditions like **Hairy cell leukemia**, and its absence is not characteristic of mantle cell carcinoma. - Thus, while CD5+ is present, the lack of CD25 alone does not define mantle cell features. **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. 610-612. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 562-563.
Explanation: ***Increased lymphadenopathy*** **(Correct Answer - This is the EXCEPTION)** - While juvenile chronic myeloid leukemia (JCML) can cause some **lymphadenopathy**, it is typically described as **mild** to **moderate**, not significantly increased. - **Prominent or markedly increased lymphadenopathy is NOT a typical feature of JCML** and would suggest a different diagnosis such as acute lymphoblastic leukemia or other lymphoproliferative disorders [1]. - This is the exception among the given options, as it does NOT characterize JCML. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a **common and typical feature** of juvenile chronic myeloid leukemia (JCML) due to bone marrow infiltration and increased platelet turnover [2]. - It often contributes to bruising and bleeding tendencies observed in affected children. *Mild lymphadenopathy* - **Mild lymphadenopathy** is a feature often observed in juvenile chronic myeloid leukemia (JCML), reflecting involvement of the reticuloendothelial system [1]. - This mild degree of lymph node enlargement is generally not prognostically significant and helps differentiate from more aggressive lymphoproliferative disorders. *Philadelphia chromosome is negative* - Juvenile chronic myeloid leukemia (JCML) is characterized by the **absence of the Philadelphia chromosome (Ph chromosome)**, which is a key diagnostic criterion. - This distinguishes JCML from adult chronic myeloid leukemia (CML), where the Ph chromosome (t(9;22) translocation) is present in >95% of cases. - The Ph-negative status is an essential feature of JCML diagnosis. **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. 625-629. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 604-605.
Explanation: ***Mean Corpuscular Volume (MCV)*** - **MCV** measures the **average volume of red blood cells**, making it the primary indicator for classifying them as microcytic, normocytic, or macrocytic. - An **elevated MCV** (typically above 100 fL) indicates **macrocytosis**, meaning the red blood cells are larger than normal. *Mean Corpuscular Hemoglobin Concentration (MCHC)* - **MCHC** reflects the **average concentration of hemoglobin** in red blood cells, primarily used to classify cells as normochromic or hypochromic. - It does **not directly measure cell size** and therefore is not used to diagnose macrocytosis. *Hematocrit* - **Hematocrit** measures the **percentage of red blood cells** in a given volume of blood. - While it indicates the overall red cell mass, it **does not provide information about the average size** of individual red blood cells. *None of the options* - As **MCV** is explicitly listed and is the correct parameter for diagnosing macrocytosis, this option is incorrect. - The other parameters listed are important for other aspects of red blood cell analysis but not for classifying cell size.
Explanation: ***Hodgkin disease*** - The presence of **painless cervical lymphadenopathy**, night sweats, and **generalized pruritus** is classical for Hodgkin lymphoma [3][4]. - Histological findings of **broad bands of fibrosis** and a mixture of cell types including **Reed-Sternberg cells** confirm the diagnosis [1][2][3]. *Non-Hodgkin lymphoma* - Typically presents with **rapidly enlarging lymph nodes** and is often associated with extra-nodal involvement, differing from the features in this case [3]. - Histology usually shows a more homogeneous population of **malignant lymphoid cells**, not the fibrotic bands seen in Hodgkin disease [3]. *Reactive non-specific lymphadenitis* - This condition is characterized by **hyperplastic lymphoid tissue** and **neutrophilic infiltration**, often following infection, which does not match the findings. - It typically lacks the distinct cell types and fibrosis observed in the biopsy of Hodgkin disease. *Cat-scratch disease* - Caused by *Bartonella henselae*, it often presents with **granulomatous lymphadenopathy** rather than the mixed cellular response seen in Hodgkin disease. - Symptoms usually include a history of cat exposure and may present with **fever, fatigue**, and localized lymphadenopathy, not generalized pruritus. **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. 616-618. [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. 616. [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. 614-616. [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. 618.
Explanation: **CD4+/CD8+ T-cell ratio in AIDS** - **Flow cytometry** is an ideal technique for identifying and quantifying specific cell populations based on their surface markers, like **CD4+** and **CD8+ T-cells**. - Monitoring the **CD4+/CD8+ ratio** is crucial in managing **AIDS** to assess immune status and disease progression. *Serum level of LDH* - **LDH (lactate dehydrogenase)** is an enzyme measured through **biochemical assays** in serum, not flow cytometry. - Flow cytometry measures cellular characteristics, while LDH levels reflect enzyme activity or tissue damage. *To count the RBCs in blood* - While flow cytometry can count cells, a **complete blood count (CBC)**, typically performed by automated hematology analyzers, is the standard and more efficient method for **RBC counting**. - Counting RBCs individually is not the primary or best use case for the advanced capabilities of flow cytometry. *Separation of proteins* - **Protein separation** is achieved through techniques like **electrophoresis**, chromatography, or mass spectrometry, not flow cytometry. - Flow cytometry is designed for analyzing and sorting individual cells or particles, not isolating protein mixtures.
Explanation: ***May-Hegglin anomaly*** - **Dohle bodies** are characteristic inclusions in neutrophils, formed by aggregates of **rough endoplasmic reticulum**, and are a defining feature of **May-Hegglin anomaly**. - This condition also presents with **macrothrombocytopenia** and a tendency for bleeding, along with the presence of these distinctive inclusions. *Infections* - While infections can cause **toxic granulation** and sometimes **Dohle bodies** in neutrophils, they are not considered a hereditary condition. - The Dohle bodies seen in infections are typically transient and not associated with macrothrombocytopenia. *Burns* - Similar to infections, severe burns can induce **toxic changes** in neutrophils, including the formation of Dohle bodies. - However, burns are an acquired condition and not a hereditary disorder, nor are they typically associated with the other features of May-Hegglin anomaly. *Myelodysplastic syndrome* - This is a clonal hematopoietic stem cell disorder characterized by **ineffective hematopoiesis** and **dysplastic changes** in myeloid cells. - While various abnormalities can be seen in neutrophils in MDS, **Dohle bodies** as a characteristic hereditary feature are not typically associated with it; instead, other dysplastic features like hypogranulation or pseudo-Pelger-Huët anomaly are more common.
Explanation: ***t (15;17)*** - The **t(15;17) translocation** is pathognomonic for **acute promyelocytic leukemia (APL, AML-M3)**, a specific subtype of AML characterized by abnormal promyelocytes [1]. - **APL rarely presents with extramedullary involvement** or myeloid sarcoma. The leukemic cells in APL typically remain confined to the bone marrow and peripheral blood [2]. - This makes t(15;17) the chromosomal abnormality **NOT typically associated** with myeloid sarcoma, unlike the other options listed [1]. *Monosomy 7* - **Monosomy 7** is a recurrent chromosomal abnormality associated with a poor prognosis in myeloid malignancies, including various forms of **acute myeloid leukemia (AML)** and **myeloid sarcoma**. - It indicates a loss of an entire chromosome 7, often linked to **myelodysplastic syndromes (MDS)** and therapy-related AML, both of which can present with myeloid sarcoma. *Trisomy 8* - **Trisomy 8** is one of the most common cytogenetic abnormalities found in **AML** and is **frequently observed in cases of myeloid sarcoma**. - It involves an extra copy of chromosome 8 and is associated with an intermediate prognosis. - Myeloid sarcomas with trisomy 8 can occur at various anatomic sites. *inv (16)* - **Inv(16)(p13q22)** is a specific chromosomal inversion associated with **acute myeloid leukemia (AML)** with **myelomonocytic differentiation** and **abnormal eosinophils** [1]. - This inversion leads to the formation of the **CBFB-MYH11 fusion gene**, and AML with inv(16) **can present as myeloid sarcoma**, particularly in soft tissues [1]. - This is a recognized chromosomal abnormality in myeloid sarcoma cases. **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] 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. 621-622.
Explanation: ***Essential Thrombocythemia*** - **Essential thrombocythemia (ET)** is the **most common myeloproliferative neoplasm**, with an incidence of approximately 1.5-2.4 per 100,000 per year. - It is characterized by **persistent thrombocytosis** (platelet count >450,000/μL) and megakaryocytic proliferation [1]. - Commonly associated with **JAK2 V617F mutation** (~55-60%), **CALR mutations** (~25-30%), and **MPL mutations** (~3-5%) [2]. *Polycythemia rubra vera* - **Polycythemia vera (PV)** is the **second most common** classic MPN, with an incidence of approximately 0.8-2.3 per 100,000 per year. - Characterized by increased red blood cell mass, often with leukocytosis and thrombocytosis [1]. - Strongly associated with **JAK2 V617F mutation** (present in >95% of cases) [2][3]. *CML* - **Chronic myeloid leukemia (CML)** has similar incidence to PV (approximately 1-2 per 100,000 per year). - Defined by the presence of the **Philadelphia chromosome (BCR-ABL1 fusion gene)** [2]. - Treated distinctly with tyrosine kinase inhibitors (TKIs). *Myelofibrosis* - **Primary myelofibrosis (PMF)** is the **least common** of the classic MPNs, with an incidence of approximately 0.3-1.5 per 100,000 per year. - Characterized by bone marrow fibrosis, extramedullary hematopoiesis, and splenomegaly [3]. - Associated with **JAK2, CALR, or MPL mutations** [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, pp. 627-628. [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. 624. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 614-615.
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