Color Atlas of Hematology - Practical Microscopic and Clinical ...

78Abnormalities of the White Cell SeriesThe pathological staging for CLL is always Ann Arbor stage IV because thebone marrow is affected. In the classifications of disease activity by Raiand Binet (analogous to that for leukemic immunocytoma), the transitionbetween stages is smooth (Tables 8 and 9).Lymphoplasmacytic LymphomaThe CBC shows lymphocytes with relatively wide layers of cytoplasm. Thebone marrow contains a mixture of lymphocytes, plasmacytic lymphocytes,and plasma cells. In up to 30% of cases paraprotein is secreted, predominantlymonoclonal IgM. This constitutes the classic Waldenströmsyndrome (Waldenström macroglobulinemia). The differential diagnosismay call for exclusion of the rare plasma cell leukemia (see p. 82) and oflymphoplasmacytoid immunocytoma, which is closely related to CLL (seep. 74).Characteristics➤ Lymphoplasmacytoid immunocytoma: This is a special form of B-CLL in which usually only a few precursors migrate into the bloodstream(a lesser degree of malignancy). A diagnosis may only bepossible on the basis of bone marrow or lymph node analysis.➤ Lymphoplasmacytic lymphoma: Few precursors migrate into thebloodstream (i.e., bone marrow or lymph node analysis is sometimesnecessary). There is often secretion of IgM paraprotein,which can lead to hyperviscosity.Further diagnostics: Marker analyses in circulating cells, lymph node cytology,bone marrow cytology and histology, and immunoelectrophoresis.Plasmacytoma cells migrate into the circulating blood in appreciablenumbers in only 1–2% of all cases of plasma cell leukemia. Therefore, paraproteinsmust be analyzed in bone marrow aspirates (p. 82).Facultative Leukemic Lymphomas(e.g., Mantle Cell Lymphoma and Follicular Lymphoma)In all cases of non-Hodgkin lymphoma, the transformed cells may migrateinto the blood stream. This is usually observed in mantle cell lymphoma:The cells are typically of medium size. On close examination, their nucleishow loosely structured chromatin and they are lobed with small indentations(cleaved cells). Either initially, or, more commonly, during the courseof the disease, a portion of cells becomes larger with relatively enlargednuclei (diameter 8–12 µm). These larger cells are variably “blastoid.” Lymphoidcells also migrate into the blood in stage IV follicular lymphoma.