Unusual B-cell lymphoproliferative disorders and the new WHO classification

Summary

There is a group of chronic B-cell lymphoproliferative disorders that at this time are difficult to classify, many of which are thought to originate in the spleen. The terms B-cell lymphoma with villous lymphocytes, hairy cell leukemia variant, and splenic diffuse red pulp small lymphocytic lymphoma have been used. The WHO puts some of these entities into the splenic B-cell lymphoma/leukemia unclassifiable category.

We have studied a group of such disorders-which have come to us for consultation – with a variety of diagnoses, including: hairy cell leukemia, hairy cell leukemia variant, splenic marginal zone leukemia, prolymphocytic leukemia, and atypical chronic lymphocytic leukemia. In addition to morphological evaluations and flow cytometric immunophenotyping, immunohistochemical and cytogenetic studies were performed in an attempt to achieve a clinically useful diagnosis.

Keywords

chronic lymphoproliferative disorders, splenic lymphomas