Composite Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma and T-Prolymphocytic Leukemia Presenting with Lymphocytosis, Skin Lesions, and Generalized Lymphadenopathy

Figure 1

Composite chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and T-prolymphocytic leukemia (T-PLL). This lymph node shows partial effacement of the architecture by a vaguely nodular/follicular proliferation of small-to-medium-sized lymphocytes surrounded by a dense infiltrate of small-to-intermediate-size lymphocytes. Hematoxylin and eosin stain (a–c). Immunohistochemistry shows that the nodular/follicular areas react with the B-cell marker CD20 (d), whereas the interfollicular areas are highlighted with the T-cell marker CD3 (e, f). Note that the follicular areas are also faintly positive with CD5 (g) and dimly positive with CD23 (h), supporting CLL/SLL (h). This distribution of CLL/SLL centered on follicular dendritic cell meshworks highlighted with CD23 is extremely unusual and supports the so-called follicular pattern of CLL/SLL.

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