Practice questions answers Lymphoid neoplasms III

Practice questions answers

Lymphoid neoplasms III

© Jun Wang, MD, PhD

 

1. C. This case is characterized by acute onset anemia, marked leukocytosis and thrombocytopenia. Peripheral blood smear reveals immature cells with scant agranular cytoplasm and large nuclei with fine chromatin. These are highly suggestive of the presence of blast and acute leukemia. Flow-cytometry may identify the type and number of these blasts in order to diagnose acute myeloid leukemia, or acute lymphoblastic leukemia. Blood culture is used for bacterial infection involving blood stream, such as sepsis. Bone marrow biopsy can be used in diagnosing marrow associated disorders, such as anemia and hematopoietic neoplasms, especially myeloid neoplasms. However, flow cytometry can accurately measure the level of blasts in either marrow or blood. Hemoglobin electrophoresis is used to diagnosing hemoglobin abnormalities. Lymph node biopsy may be used to diagnose a localized disorder involving a lymph node. But this is patient already have blood involvement, so lymph nodes biopsy will have limited significance.

2. F. These CD33 and CD34 positive blasts also express T cell marker CD3, but not B-cell markers CD19 and CD20, not myelocytic marker myeloperoxidase, confirming their T-cell origin. There are more than 20% blasts, consistent with the diagnosis of T-cell acute lymphoblastic leukemia. Acute myeloid leukemia usually are positive for myeloperoxidase, but negative for T or B cell markers, and lymphoblast marker TdT. B-cell acute lymphoblastic leukemia express B-cell markers, such as CD19 and CD20, but not T-cell markers. Chronic myelogenous leukemia have increased less mature myelocytic series and less than 20% myeloblast, but should not have the presence of lymphoblasts. Chronic lymphocytic leukemia is characterized by increased number of small lymphocytes. Hairy cell leukemia is a B-cell neoplasm characterized by pancytopenia, and the presence lymphocytes with hairy projects.

3. E. Notch1 mutation is commonly seen in T-cell acute lymphoblastic leukemia. BRAF mutation can be seen in hairy cell leukemia, melanocytic nevus and melanoma. C-myc mutation can be seen in Burkitt lymphoma. ETV6 and MLL abnormalities can be seen in B-cell acute lymphoblastic leukemia.

4. B. See discussion of question 1. Iron and lead studies may be used to diagnose iron deficiency anemia or anemia associated with lead poisoning. Even though this patient has anemia, presence of lymphoblasts is more consistent with a hematopoietic neoplasm. The bone pain in this patient is most likely associated with marrow abnormalities, so radiology studies would have limited significance.

5. B. See discussion of question 2.

6. A. Cytogenetic study finding of 9:22 translocation is most consistent with BCR::ABL fusion. Other genes are not associated with this translocation.

7. D. This case is characterized by indolent clinical course and peripheral blood finding of markedly increased number of small lymphocytes with “soccer ball” appearing nuclei. These lymphocytes are positive for pan-B cell markers CD19 and CD20, and positive for CD5 and CD23. This immunohistochemistry profile is consistent with chronic lymphocytic leukemia. Also see discussion of question 2.

8. D. This case is characterized by lymphoid proliferation in a follicular pattern. These cells are positive for B-cell marker CD20 but not T-cell marker CD3, suggesting this is a B-cell neoplasm. The immunohistochemistry profile of positive reactivity to CD10 but negative for CD5, and expression of bcl2 in the center of these follicular structures is consistent with follicular lymphoma. MLL2 and t(14;18)(q32;q21) involving bcl2 are very common in follicular lymphoma. inv(16)(p13.1;q22) is seen in AML with inv(16)(p13.1;q22). t(11;14)(q13;q32) can be seen in mantle cell lymphoma. t(11;18)(q21;q21) involving API2 and MALT1 can be seen in marginal zone lymphoma. t(15;17)(q22;q12) involving RARA can be seen in APL. Trisomy 12 can be seen in chronic lymphocytic leukemia.

9. B. t(14;18)(q32;q21) results in rearrangement of bcl-2 and IgH. BCR::ABL fusion is commonly a results of 9:22 translocation. IGH-CCND1 is a result of t(11;14)(q13;q32) in mantle cell lymphoma. API2-MALT1 rearrangement may be resulted from t(11;18)(q21;q21) in marginal zone lymphoma. MYD88 mutation can be seen in lymphoplasmacytic lymphoma.

10. D. See discussion of question 8. Adult T cell lymphoma usually has tumor cells with multilobated nuclei, and positive for CD3 and CD4, but not for B cell markers, ALK or CD30. Burkitt lymphoma has monotonous round cells expressing CD20 and CD10, but will not form follicular structures. Diffuse large B-cell lymphoma tends to have sheets of large atypical B cells, without follicular pattern. Mantle cell lymphoma is positive for CD5 and cyclin D1, but negative for CD10 and bcl2. Marginal zone lymphoma is positive for CD20, but negative for CD5, CD10 and cyclin D1.

11. C. This case is characterized by generalized lymphadenopathy, splenomegaly and small atypical lymphocytes in circulation. Lymph nodes biopsy reveals diffuse infiltrate of small lymphocytes. These cells are positive for CD5, CD20 and cyclin D1, but negative for other T cell markers and CD23. When there is a lymphoma/leukemia of small lymphocytes, the top differentials include chronic lymphocytic leukemia and mantle cell lymphoma. Chronic lymphocytic leukemia is positive for CD5 and CD23, but negative for cyclin D1, but mantle cell lymphoma is positive for CD5 and cyclin D1, but negative for CD23. Also see discussion of questions 8 and 9.

12. C. See discussion of question 9.

13. D. See discussion of questions 8 and 10. Small lymphocytic lymphoma is in the same category of chronic lymphocytic leukemia, characterized by proliferation of small lymphocytes with “soccer ball” appearing nuclei, and expression CD5 and CD23, but not cyclin D1.

14. D. This case is characterized by diffuse lymphoid infiltration in a patient with a history of H. pylori gastritis. The immunohistochemistry profile of positive reactivity to B-cell marker CD20, but negative reactivities to CD5, CD10, cyclin D1 and T cell markers, is consistent with marginal zone lymphoma. Also see discussion of questions 8 and 9.

15. D. See discussion of questions 8 and 9. ALK is abnormal in anaplastic large cell lymphoma.  

16. D. Marginal zone lymphoma can be associated with various risk factors, including autoimmune disorders and infection of H. pylori. EBV is associated with various lymphomas, including classical Hodgkin lymphoma, extranodal T/NK cell lymphoma, Burkitt lymphomaand primary effusion lymphoma. HHV8 is associated with primary effusion lymphoma and Kaposi sarcoma.

17. E. See discussion of questions 10 and 14. Extranodal T/NK cell lymphoma is positive for T-cell markers and at list one of the NK cell markers, such as CD56.

18. B. This case is characterized by pancytopenia and atypical cells with round nuclei and hairy projects in peripheral blood and failed bone marrow aspirate. These cells are not blasts due to negative reactivities to CD34 and TdT. The immunohistochemistry profile of positive reactivity to B cell markers and CD11c, and negative reactivities to CD5, CD10 and CD23 is therefore consistent with hairy cell leukemia. BRAF mutation can be seen in hairy cell leukemia, melanocytic nevus and melanoma. ALK is abnormal in anaplastic large cell lymphoma. Also see discussion of question 9.

19. E. See discussion of questions 2 and 11. Fanconi anemia is a type of aplastic anemia usually with early onset and birth defects.

20. B. This case is characterized by sheets of large atypical cells expressing B cell markers, but not ALK, T/NK cell markers not cytokeratin, consistent with diffuse large B-cell lymphoma. Anaplastic large cell lymphoma is positive for T cell markers, may be positive for ALK, but usually negative for B cell markers. Hodgkin lymphoma has RS cells or popcorn cells. Also see discussion of questions 10 and 13.

 

 

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