[Immunophenotyping of B chronic lymphoproliferative syndromes (CLL excluded): confrontation with the histology]

Immunophenotyping is a major tool for the diagnosis of the chronic lymphoïd leukaemia (CLL). Its interest remains limited in the classification of the other B chronic lymphoproliférative syndromes (B-CLPS). We evaluate the place of the flow cytometry (CMF) in the diagnosis and classification of the non CLL B-CLPS. The cases with Matutes score of 4 or more are excluded. A confrontation of the results to the histology is made. 28 cases of non CLL B-CLPS are diagnosed. CMF shows a κ monoclonal population in 15 cases and λ in 13 cases. A co-expression CD19+CD5 + is found in 11 cases concording with an atypic CLL or a mantel cell lymphoma in 6 cases with Matutes score of 3. In 5 cases, we concluded to non CLL B-CLPS (Matutes<3). The histology retained the diagnosis of a mantel cell lymphoma (4 cases), a SLVL (1 case) and an atypical LLC (1 case). CD5 is negative in 17 cases. In 5 cases, the diagnosis of hairy cell leukemia (HCL) is retained (CD 11c+ CD103+) and confirmed by the histology. The diagnosis of a marginal zone lymphoma is retained in 2 cases, a SLVL in 2 cases, a follicular lymphoma in 3 cases and prolymphocytes leukaemia in 1 case. Nine cases of non CLL B-CLPS were difficult to classify by histology. CMF is insufficient for the classification of most of the non CLL B-CLPS. Only the phenotype of the HCL is characteristic. The confrontation of the histology results remains essential.