Composite prolymphocytoid and Hodgkin transformation of chronic lymphocytic leukemia

The indolent course of chronic lymphocytic leukemia/small lymphocytic lymph oma (CLL/SLL) is occasionally altered by transformation to a histologically distinct, rapidly progressive, and clinically unresponsive hematologic mal ignant neoplasm. We report a case of CLL that, after 3 years of slowly prog ressive disease and treatment with single-agent chemotherapy (fludarabine p hosphate), underwent a composite prolymphocytoid and classic Hodgkin lympho ma transformation. The diagnosis of classic Hodgkin lymphoma was based on t he presence of Reed-Sternberg cells with typical morphologic structure and immunophenotype (CD15(+), CD30(+), CD45(-), CD20(-)) associated with the ch aracteristic polymorphous inflammatory background consisting of numerous eo sinophils, plasma cells, and reactive T lymphocytes. The remainder of the l ymph node and the peripheral blood showed increased numbers of prolymphocyt es admixed with typical small CLL cells. Recognition of such a transformati on is of the utmost importance, since histologically similar Reed-Sternberg -like cells may be seen in Richter transformation. In contrast to prolympho cytoid transformation of CLL, Richter syndrome is rapidly fatal, with a med ian survival of 4 to 5 months. The patient pursued a clinical course simila r to pure prolymphocytoid transformation and died with disease after 30 mon ths following treatment with combination chemotherapy.