[Persistent polyclonal B-cell lymphocytosis: study of 35 cases].

Background And Objectives: Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare entity, presenting especially in adult smoker women. It is characterized by an increase of serum IgM, DR7-HLA haplotype, cytogenetic abnormalities and multiple IgH/BCL-2 rearrangements. To date, it has not been elucidated whether this is a benign or premalignant disorder.

Blast cells with nuclear extrusions in the form of micronuclei are associated with MYC amplification in acute myeloid leukemia.

We report three cases of acute myeloid leukemia without maturation [AML-M1 subtype according to the French-American-British classification (FAB)] with the presence of MYC oncogene amplification in form of double minutes (dmin) or homogeneously staining region (hsr). Blasts cells showed a particular morphology with extrusion of chromatin material. We observed by FISH the phenomenon of MYC aggregation in interphase cells and the formation of micronuclei excluded from the nucleus.

Cytogenetic and fluorescence in situ hybridization studies in 60 patients with multiple myeloma and plasma cell leukemia.

We report cytogenetic results in a series of 60 patients affected with multiple myeloma (MM) and plasma cell leukemia (PCL) and compare the results with those previously reported. In our series, a total of 41% of MM patients and 71% of PCL patients displayed chromosome abnormalities. To evaluate the clinical value of monosomy 18, we obtained fluorescence in situ hybridization results (using centromeric probe for chromosome 18) of 22 MM patients who displayed a normal karyotype.