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Lecture 22
Malignant Lymphoma: Non-Hodgkin Lymphoma
Question | Answer |
---|---|
(T or F) There are no recognized benign neoplasma of the hematopoietic-lymphoid system. | True. |
(T or F) Lymphomas are clonal. | True. These neoplasms contain clonal expansions of a single functional subpopulation |
(T or F) The site of the primary disease of Non-Hodgkin Lymphomas is important. | True. |
What is the most common type of non-Hodgkin's lymphoma in the Western World? | B-cell Non-Hodgkin Lymphomas make up 85-80% of all non-Hodgkin Lymphomas. |
What is the characteristic immunophenotypic profile of follicular lymphoma? | CD20+ (pan B-cell), CD10+, and abundant monotypic surface immunoglobulin. |
Type of NHL that classically presents with peripheral or retroperitoneal adenopathy. Histologic features include: effacement of nodal architecture by proliferation of neoplastic follicular nodules composed of small cleaved cells. | Follicular Lymphoma |
What is the cell of origin in Follicular Lymphoma? | B follicular center cells |
What is defined as Grade I follicular lymphoma? | Follicular lymphoma mostly composed of small cleaved cells |
What is defined as Grade II follicular lymphoma? | Follicular lymphoma composed of a mixture of small cleaved and large transformed cells |
What is defined as Grade III follicular lymphoma? | Follicular lymphoma largely made up of large cells. |
What is the predominant genotype of follicular lymphomas? | t(14;18): This translocation juxtaposes the BCL-2 oncogene into the Ig heavy chain locus on chromosome 14 leading to the expression of Bcl-2 protein which blocks apoptotic cell death. |
What is the immunophenotypic profile of B-Small Lymphocytic Lymphoma (B-SLL)? | Weak CD20, CD5, CD23, and weak surface immunoglobulin. |
Type of NHL that occurs in older adults that presents with adenopathy and a leukemic blood picture identical to B-chronic lymphocytic leukemia. | B-Small Lymphocytic Lymphoma (B-SLL) |
What are the histologic characteristics of B-Small Lymphocytic Lymphoma (B-SLL)? | Involved lymph nodes show diffuse effacement by a proliferation of small lymphocytes with round nuclei and dense chromatin. |
Is a B-Small Lymphocytic Lymphoma (B-SLL) tumor considered high grade or low grade? | Low grade |
What are common sites of MALT Lymphomas? | Extranodal tissue of the GI tract and lungs. |
(T or F) MALT lymphomas only arise from lymphoid tissue that is a normal component of the site of origin (eg Peyer's patches of the small intestines). | False. MALT lymphomas may also arise from lymphoid tissue acquired as part of an autoimmune disorder or infeciton. |
What is the immunophenotypic profile of Mantle Cell Lymphoma (MCL)? | CD20+, CD5+, CD23-, and Surface Ig+ |
What is the characteristic genotype of Mantle Cell Lymphomas? | t(11;14)(q13;q32) translocation |
What is the molecular defect associated with t(11;14)(q13;q32) translocation? | Translocation of the immunoglobulin heavy chain gene next to the CYCLIN D1 (Bcl-1) gene, which leads to the overexpression of CYCLIN D1. |
Type of NHL that occurs almost exclusively in adults characterized by diffuse proliferation of large neoplastic B-lymphoid cells. | Diffuse Large B-cell Lymphoma (DLBCL) |
Where is the endemic form of Burkitt Lymphoma found? | Young children of Africa |
Where is the sporadic form of Burkitt Lymphoma found? | Children of all ages in the United States |
Type of NHL that presents in extra-nodal sites such as the jaws, distal ileum, and ovaries. Morphologically, it demonstrates a diffuse proliferation of small noncleaved cells with a very high mitotic rate and a background of "starry sky" macrophages. | Burkitt Lymphoma |
What virus plays an important role int he pathogenesis of Burkitt Lymphoma? | Epstein-Barr Virus |
What is the immunophenotypic profile of Burkitt Lymphoma neoplastic cells? | CD20+, CD10+, and surface Ig+ |
What is the genotype of Burkitt Lymphoma neoplastic cells? | Translocation of the MYC gene on chromosome 9 to the Ig heavy chain on chromsome 14. Or, the translocation of the MYC gene to the light chain loci on chromsome 2 or 22. |
Type of NHL that classically presents as a rapidly growing anterior mediastinal mass in young patients, often male, who may have a respiratory or CV compromise and pleural/pericardial effusion. This lympohma disseminate rapidly to marrow, blood, and LNs. | Precursor T-lymphoblastic Lymphoma (T-LL) |
What is the histologic findings of thymic tissue in Precursor T-lymphoblastic Lymphoma (T-LL)? | Thymic tissue is effaced by diffuse growth of monomorphic tumor cells that have high mitotic rate, and invade the capsule. The tumor cell hsave a blastic appearance. |
What is the immunophenotypic profile of Precursor T-lymphoblastic Lymphoma (T-LL) neoplastic cells? | Immunophenotypic markers of immature T cells |
Type of NHL that is a tumor of small, skin based T0cells, predominantly of the CD4+ subset that occurs in adults. The neoplastic lymphocytes are small and have a characteristic folded, cerebriform nucleus. | Mycosis Fungoides (MF) |
What is the histologic findings of Mycosis Fungoides (MF)? | Band-like superifical dermal infiltrate adjacent to and invading the epidermis with formation of small collections of lymphocytes in the epidermis. The lymphocytes are small and have a characteristic folded, cerebriform nucleus. |
Definition of epidermotropism | The invasion of the epidermis by a band-like superficial dermal infiltrate of neoplastic lymphocytes in mycosis fungoides (MF). |
Defintion of Pauter's microabscess | Small collection of neoplastic lymphocytes in the epidermis in mycosis fungoides (MF). |
Type of NHL that is characterized by constitutional symptoms with paraneooplastic features (eg eosinophilia and hemophagocytosis). Most cases demonstrate a T-phenotype with loss or aberrant expression of pan T-cell antigens. | Peripheral T-cell Lymphoma (PTCL) |