This chapter outlines the category of preneoplastic and neoplastic lymphocyte and plasma cell disorders. It introduces a framework for evaluating neoplastic lymphocyte and plasma cell disorders, outlines clinical syndromes associated with such disorders, and guides the reader to the chapters in the text that discuss each of these disorders in greater detail.
Lymphocyte and plasma cell malignancies present a broad spectrum of different morphologic features and clinical syndromes (Table 1–1). Lymphocyte neoplasms can originate from cells that are at a stage prior to T- and B-lymphocyte differentiation from a primitive stem cell or from cells at stages of maturation after stem cell differentiation. For example, acute lymphoblastic leukemias arise from an early lymphoid progenitor cell that may give rise to cells with either B- or T-cell phenotypes (Chap. 2), whereas chronic lymphocytic leukemia arises from a more mature B-lymphocyte progenitor (Chap. 3) and myeloma from progenitors at even later stages of B-lymphocyte maturation (Chap. 18). Disorders of lymphoid progenitors may result in a broad spectrum of lymphocytic diseases, such as B- or T-cell lymphomas (Chaps. 9 and 15), hairy cell leukemia (Chap. 4), prolymphocytic leukemia (Chap. 3), natural killer cell large granular lymphocytic leukemia (Chap. 5),1 myeloma, and plasmacytoma (Chap. 18). Hodgkin lymphoma also is derived from a neoplastic B cell that has highly mutated immunoglobulin genes that are no longer expressed as protein (Chap. 8).
TABLE 1–1.Classification of Lymphoma and Lymphoid Leukemia by the World Health Organization ||Download (.pdf) TABLE 1–1. Classification of Lymphoma and Lymphoid Leukemia by the World Health Organization
|Neoplasm ||Morphology ||Phenotype* ||Genotype† |
|B-CELL NEOPLASMS |
|Immature B-Cell Neoplasms |
| Lymphoblastic leukemia/lymphoma not otherwise specified (NOS) (Chap. 2) ||Medium-to-large cells with finely stippled chromatin and scant cytoplasm ||TdT+, sIg–, CD10+, CD13+/–, CD19+, CD20–, CD22+, CD24+, CD34+/–, CD33+/–, CD45+/–, CD79a+, PAX5+ ||Clonal DJ rearrangement of IGH gene T(17;19), E2A-HLF, AML1 iAMP21 associated with poor prognosis |
| Lymphoblastic leukemia/lymphoma with recurrent genetic abnormalities (Chap. 2) ||See above ||See above. B-ALL with t(9;22) with CD25 and more frequent myeloid antigens CD13, CD33 ||See individual genetic features in B-ALL subtypes below |
| B-ALL with t(v;11q23); MLL rearranged ||See above ||CD19+, CD10–, CD24–, CD15+ ||Multiple MLL (11q23) fusion partners, including AF4 (4q21), AF9 (9p22), and ENL (19p13). B-ALL with MLL translocations overexpress FLT-3. Poor prognosis |
| B-ALL with t(12;21)(p13;q22); TEL-AML1 (ETV6-RUNX1) ||See above ||CD19+, CD10+, CD34+. Characteristically negative for CD9, CD20, and CD66c ||t(12;21)(p13;q22) ETV6-RUNX translocation |
| B-ALL with hyperdiploidy ||See above ||CD19+, CD10+, CD45–, CD34+ ||Numerical increase in chromosomes without structural abnormalities. Most frequent chromosomes +21, X, 14, and 4. +1, 2, 3 rarely seen. Favorable prognosis |
| B-ALL with hypodiploidy ||See above ||See above ||Loss of at least one or more chromosomes (range from 45 ...|