CD5- B-cell lymphoproliferative disorders presenting in blood and bone marrow. A clinicopathologic study of 40 patients.

We studied 40 patients with CD5- B-cell lymphoproliferative disorders (B-LPDs) presenting in blood or bone marrow and 28 control patients with CD5+ B-cell chronic lymphocytic leukemia (CLL). Fifteen study patients had morphologic features typical of CLL. The 15 patients with CD5- CLL were older and had lower absolute lymphocyte counts and more advanced-stage disease at diagnosis than controls. Ten study patients had morphologic features suggesting mantle cell lymphoma (MCL); 3 were later given a diagnosis of MCL based on lymph node biopsy results. The 10 patients with CD5- MCL were older and at a more advanced stage than CLL control patients. The remaining 15 study patients were given the following diagnoses: circulating non-Hodgkin lymphoma, 5; splenic lymphoma with villous lymphocytes, 5; lymphoplasmacytoid lymphoma, 3; and CLL/pro-lymphocytic leukemia, 2. For the patients with CD5- B-LPDs with morphologic features and manifestations resembling CLL, we prefer the term CD5- CLL variant because of clinical and immunophenotypic differences. Patients with CD5- B-LPDs with atypical nuclear morphologic features may represent the leukemic phase of MCL. Since CD23 is expressed in most patients with CD5- B-LPD, its use in subclassifying these disorders seems limited.