atypical CLL, including the CLL/PL (prolymphocytic leukemia) or CLL mixed-cell-type variant by FAB criteria

virgin CD5+ recirculating B-cell

del(13q) is found in approximately 10-15% of all CLLs

the clinical course may be more aggressive than in typical CLL, depending on stage at presentation and % of prolymphocytes

splenic lymphoma with villous lymphcytes

chronic proliferation originating from the marginal zone B-lymphocytes

the disorder appears to be relatively rare, but it is probably underdiagnosed

the clinical course is indolent

leukemic mantle cell lymphoma

the majority of mantle cell lymphomas show peripheral blood (PB) involvement at diagnosis or at disease evolution; there is a disease variant presenting as a de novo leukemic condition, presenting heterogeneous cytological features with PB and BM lymphocytosis, without adenopathy, with or withour splenomegaly; some of these cases may fulfill the FAB criteria for the diagnosis of atypical CLL; because these cases usually carry the t(11;14)(q13;q32) and a mantle-cell phenotype, they have also been referred to as "mantle cell leukemia": it is reasonable to assume that the transformation of a mantle cell may give rise to a spectrum of diseases ranging from the classical lymphomatous form of MCL to an overt leukemic condition, as is the case with small lymphocytic lymphoma and chronic lymphocytic leukemia

proliferation of cells of follicle mantle lineage (CD5/CD19/CD22 positive, CD23 negative, bright sIg expression)

a spectrum of B-cell chronic lymphoproliferative disorders (CLD) may carry a chromosome 13q deletion; among these, three forms other than chronic lymphocytic leukemia (CLL)were identified by the FAB group which may frequently carry a 13q- chromosome: atypical CLL, splenic lymphoma with villous lymphocytes, corresponding to splenic marginal zone B-cell lymphoma, and mantle cell lymphoma (MCL) in leukemic phase