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.
Acronyms and Abbreviations
α/β TCR, T-cell-receptor genes encoding the α and β chains of the T-cell receptor (Chap. 76); ALK, gene encoding anaplastic lymphoma kinase; BCL2, gene encoding B-cell chronic lymphocytic leukemia (CLL)/lymphoma 2; BCL6, gene encoding B-cell chronic lymphocytic leukemia (CLL)/lymphoma 6; cIg, cytoplasmic immunoglobulin; CNS, central nervous system; DLBCL, Diffuse large B cell lymphoma (Chapter 97); EBER, Epstein-Barr-virus-encoded RNA; EBV, Epstein-Barr virus; γ/δ TCR, T-cell-receptor genes encoding the γ and δ chains of the T-cell receptor (Chap. 76); HL, Hodgkin lymphoma; HLA, human leukocyte antigen; HTLV-1, human T-cell leukemia virus type 1; HHV8, human herpes virus 8; Ig, immunoglobulin; IgR, immunoglobulin gene rearrangement (Chap. 75); IL, interleukin; MALT, mucosa-associated lymphoid tissue; MUM1, gene encoding multiple myeloma oncogene 1; neg., negative; NK cell, natural killer cell; NOS, not otherwise specified; NPM, gene encoding nucleophosmin; PAX5, paired box gene 5; POEMS, polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes; REAL, revised European-American lymphoma; R-S, Reed-Sternberg; sIg, surface immunoglobulin (Chap. 74 and 75); sIgD, surface immunoglobulin D; sIgM, surface immunoglobulin M; TAL1, gene encoding T-cell acute leukemia-1; TCR, T-cell receptor; TdT, terminal deoxynucleotidyl transferase; Th2, T-helper type 2; WHO, World Health Organization.
Lymphocyte and plasma cell malignancies present a broad spectrum of different morphologic features and clinical syndromes (Table 89–1). Lymphocyte neoplasms can originate from cells across a wide spectrum of stages of T-, natural killer (NK)-, or B-lymphocyte differentiation. For example, acute lymphoblastic leukemias arise from an early lymphoid progenitor cell giving rise to cells with either pre–B- or pre–T-cell phenotypes (Chap. 90), whereas chronic lymphocytic leukemia (CLL) arises from a more mature B-lymphocyte progenitor (Chap. 91) and myeloma from progenitors at even later stages of B-lymphocyte maturation (Chap. 106). Disorders of lymphoid progenitors result in a broad spectrum of lymphocytic diseases such as B- or T-cell lymphomas (Chaps. 97–103), hairy cell leukemia (Chap. 92), prolymphocytic leukemia (Chap. 91), NK cell large, granular, lymphocytic leukemia (Chap. 93),1 myeloma, and plasmacytoma (Chap. 106). Hodgkin lymphoma also is derived from a neoplastic B cell that has highly mutated immunoglobulin genes that are no longer expressed as protein (Chap. 96).
TABLE 89–1.Classification of Lymphoma and Lymphoid Leukemia by the World Health Organization