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

74Abnormalities of the White Cell SeriesChronic Lymphocytic Leukemia (CLL) and Related DiseasesA chronic lymphadenoma, or chronic lymphocytic leukemia, can sometimesbe clinically diagnosed with some certainty. An example is the caseof a patient (usually older) with clearly enlarged lymph nodes and significantlymphocytosis (in 60% of the cases this is greater than 20 000/µl andin 20% of the cases it is greater than 100 000/µl) in the absence of symptomsthat point to a reactive disorder. The lymphoma cells are relativelysmall, and the nuclear chromatin is coarse and dense. The narrow layer ofslightly basophilic cytoplasm does not contain granules. Shadows aroundthe nucleus are an artifact produced by chromatin fragmentation duringpreparation (Gumprecht’s nuclear shadow). In order to confirm the diagnosis,the B-cell markers on circulating lymphocytes should be characterizedto show that the cells are indeed monoclonal. The transformedlymphocytes are dispersed at varying cell densities throughout the bonemarrow and the lymph nodes. A slowly progressing hypogammaglobulinemiais another important indicator of a B-cell maturation disorder.Transition to a diffuse large-cell B-lymphoma (Richter syndrome) israre: B-prolymphocytic leukemia (B-PLL) displays unique symptoms. Atleast 55% of the lymphocytes in circulating blood have large centralvacuoles. When 15–55% of the cells are prolymphocytes, the diagnosis ofatypical CLL, or transitional CLL/PLL is confirmed. In some CLL-like diseases,the layer of cytoplasm is slightly wider. B-CLL was defined as lymphoplasmacytoidimmunocytoma in the Kiel classification. According tothe WHO classification, it is a B-CLL variation (compare this with lymphoplasmacyticleukemia, p. 78). CLL of the T-lymphocytes is rare. The cellsshow nuclei with either invaginations or well-defined nucleoli (T-prolymphocyticleukemia). The leukemic phase of cutaneous T-cell lymphoma(CTCL) is known as Sézary syndrome. The cell elements in this syndromeand T-PLL are similar.Fig. 23 CLL. a Extensive proliferation of lymphocytes with densely structured nuclei and little variation in CLL. Nuclear shadows are frequently seen, a sign ofthe fragility of the cells (magnification 400). b Lymphocytes in CLL with typicalcoarse chromatin structure and small cytoplasmic layer (enlargement of a sectionfrom 23 a, magnification 1000); only discreet nucleoli may occur. c Slightlyeccentric enlargement of the cytoplasm in the lymphoplasmacytoid variant ofCLL.