Elisabet Lloveras

Translocation (11;14)(q13;q32) and Preferential Involvement of Chromosomes 1, 2, 9, 13, and 17 in Mantle Cell Lymphoma

We have studied 13 cases of histologically confirmed mantle cell lymphomas (MCL) combining cytological-immunological features with conventional cytogenetics and in situ hybridization (ISH) techniques. Peripheral blood smears and lymph node biopsies expressed the typical mantle zone pattern with alpha B-cell phenotype. Most of the cases (11 of 13) had lymphomatous cells in the peripheral blood. Chromosome analysis was carried out on lymphoid cells from peripheral blood and/or lymph node biopsies. Phytohemagglutinin (PHA) and phorbol 12-myristate 13 acetate (TPA) were used as mitogens. Biotin-labeled libraries of whole chromosomes implicated in complex karyotypes were used to improve their interpretation. Clonal chromosome abnormalities were found in 10 of 13 patients (77%); 7 of these had a complex abnormality. The most frequent recurrent structural abnormalities were: t(11;14)(q13;q32), involvement of chromosome 1 (der[1], del[1], dup[1]), chromosome 2 (del[2], der[2]), chromosome 9 (der[9], -9), chromosome 13 (add[13], t[13q]), and chromosome 17 (add[17], der[17], t[17q]). The most frequent numerical abnormalities were monosomy 21 and loss of the Y chromosome.

Cytogenetic Findings in Five Patients with Hairy Cell Leukemia

We studied five cases of hairy cell leukemia (HCL) using conventional cytogenetics. All patients were diagnosed with typical HCL. Chromosome analysis was carried out on a 72-hour culture of peripheral blood. Phytohemagglutinin (PHA) mitogen was used. Clonal chromosome abnormalities were found in 2/5 patients (40%), a complex abnormality being identified in one of them. The chromosomes involved were: 1, 6, 7, 8, and 17. No patient showed trisomy 12 or a 14q+. An interesting result was the finding of del(7)(q32) as a sole anomaly.

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. Monosomy 18 was present in 3 of 22 patients (14%). Using conventional cytogenetics, we detected monosomy 18 in one patient affected with PCL. Two of four cases with monosomy 18 followed an aggressive course, with overall survival of 1 and 9 months. The remaining two are in follow-up and remain stable. The association of monosomy 18 with IgA subtype predominance and poor prognosis was not observed in this series of MMs and PCLs. Although these results do not confirm our previous hypothesis, further observations of this group of patients (with monosomy 18) regarding malignant transformation is warranted.

Cytogenetic Abnormalities in Three Patients with B-Cell Prolymphocytic Leukemia

We present the cytological features, conventional cytogenetics, and in situ hybridization (ISH) findings of three cases of B-cell prolymphocytic leukemia (B-PLL). The diagnosis was made according to the French-American-British (FAB) criteria. We considered a diagnosis of B-PLL when a predominance (> 50%) of lymphoid cells with coarse chromatin but prominent central nucleoli and more abundant cytoplasm than typical chronic lymphocytic leukemia (CLL) cells were present. B-PLL express strong SIg, B-cell antigens, and reactivity with the monoclonal antibody FMC7. Chromosome analysis was carried out on lymphoid cells from peripheral blood and, in one patient, from lymph node. The phytohemagglutinin (PHA) mitogen was used. ISH was performed with two types of probes: the biotin-labeled chromosome 12-specific alpha satellite DNA probe to detect trisomy 12, and biotin-labeled libraries of whole chromosomes 1, 7, and 14. Clonal chromosome abnormalities were found in all three patients; in one, a complex karyotype was observed. The most frequent recurrent abnormality was trisomy 12. Our results suggest that PLL usually presents with cytogenetic abnormalities. The finding of translocation (11;14) is noteworthy; chromosomes 1 and 3 are also involved.

Dicentric (17;18) in a Case of Atypical B-Cell Chronic Lymphocytic Leukemia

We report a new dic(17;18)(p11.2;p11.2) in a 61-year-old male patient diagnosed with atypical B-cell chronic lymphocytic leukemia. The dic(17;18)(p11.2;p11.2) was detected in 90%, 10%, and 100% of metaphases in the peripheral blood, bone marrow, and lymph node, respectively. Fluorescence in situ hybridization studies with chromosome 17 and 18 centromeric probes revealed the presence of two normal centromeres of both chromosomes 17 and 18. The centromere of one chromosome 17 was found together with the centromere of one chromosome 18, confirming the dicentric nature of the rearrangement. In addition, with the use of a 17p13.1 region probe, monosomy of the 17p13 region, where the Tp53 gene is located, was observed.

Intrachromosomal 3p Insertion as a Cause of Reciprocal Pure Interstitial Deletion and Duplication in Two Siblings: Further Delineation of the Emerging Proximal 3p Deletion Syndrome

Very few cases of constitutional interstitial deletions of the proximal short arm of chromosome 3 have been reported; however, the proximal 3p deletion is emerging as a clinically recognizable syndrome. We present an intrachromosomal insertion of 3p12.3p14.1 in a phenotypic normal man (46,XY,ins(3)(p25p12.3p14.1)) which is responsible for the unbalanced karyotype in 2 affected offspring, one with a 3p12.3p14.1 interstitial deletion and the other with a reciprocal duplication. The exceptionality of these 2 reciprocal recombinants contributes to a better definition of the proximal 3p deletion syndrome and its duplication counterpart.

Cytogenetic and fluorescence in situ hybridization studies in four cases of plasma cell leukemia.

We present a cytogenetic and fluorescence in situ hybridization (FISH) study, using centromeric probes for chromosomes 3, 7, 11, and 18, TP53 gene (17p13), and RB-1 locus (13q14) DNA probes, in four cases of plasma cell leukemia (PCL). Among the four cases, three presented monosomy of the RB-1 locus and one monoallelic deletion of the TP53 gene. The present report shows the usefulness of the FISH technique to detect abnormalities not previously observed by conventional cytogenetics.

Isochromosome +i(3)(q10) in a new case of persistent polyclonal B‐cell lymphocytosis (PPBL)

To the Editor: Persistent polyclonal B-cell lymphocytosis (PPBL) with binucleated or bilobulated lymphocytes is a disorder ®rst described by Gordon et al. (1982) in three patients. As far as we know, nearly 60 cases of PPBL have been reported since then (1±12). This entity usually affects young or middle-aged women who smoke heavily and are generally asymptomatic. Patients present moderate but sustained absolute lymphocytosis in the range (5±15)r10/L, with small numbers of circulating bilobulated forms detected in peripheral blood smears. Most patients show a polyclonal increase of serum IgM, with low to normal levels of IgA and IgG. Phenotypically, binucleated cells express both kappa and lambda light chains. Interestingly, most of the patients reported display the HLA-DR7 antigens on their lymphocytes, suggesting a genetic predisposition of the disease (2, 7, 10, 12). Cytogenetically, the presence of an additional isochromosome i(3)(q10) has been reported (3, 9, 11, 12). A 44-yr-old white female was referred to our institution for investigation of a persistent lymphocytosis present for more than 10 yr. The patient was a heavy cigarette smoker (more than 40 cigarettes a day) and presented hypercholesterolaemia. On physical examination, neither adenopathies nor hepatosplenomegaly were detected. Laboratory evaluation revealed: haemoglobin of 11 g/dL and platelet count of 219r10/L. Her leukocyte count was 10.3r10/L with 47% segmented neutrophils, 1% band forms, 48% lymphocytes, 1% monocytes, 2% eosinophils and 1% basophils. Peripheral blood smear evaluation of the lymphoid cells showed 50% mature lymphocytes, 40% large lymphocytes and 10% bilobulated lymphocytes. Blood chemistry was normal. Total serum protein was 6.4 g/dL and serum IgM was increased, reaching 794 mg/dL but without peak, while serum IgG and IgA were normal to slighly decreased (595 and 86 mg/dL, respectively). The patients serum was studied for the presence of antibodies against hepatitis B virus, hepatitis C virus and human immunode®ciency virus, all of them being negative. Low titers of antibodies against Epstein±Barr virus (EBV) and cytomegalovirus (CMV) were found. HLA-DR typing revealed expression of DR3, DR7, DRw52 and DRw53. Regarding the morphology of the peripheral blood lymphocytes, nearly half of them had a normal appearance; 40% showed an enlarged size, presence of nucleoli and a blue-stained cytoplasm. A minority of nuclei were deeply indented and eventually split into two fragments. Binucleated or bilobulated nuclei connected or not by a slender internuclear bridge were recorded in approximately 10% of the lymphocytes. The most striking ultrastructural ®ndings were nuclear pockets, found in 6 out of 25 cross-sections of mainly bilobulated lymphocytes and an abundance of multivesicular bodies. Bundles of ®brils could also be observed. Bone marrow aspirate was moderately hypercellular; the myeloid series were qualitatively and quantitatively normal. Lymphocytic series represented only 13% of the total cellularity, and no bilobulated forms were seen. Immunology studies were performed by the alkaline phosphatase antialkaline phosphatase (APAAP) method on peripheral blood ®lms. The atypical lymphocytes found in peripheral blood were CD19, HLA-DR, CD25, IgM, CD11c, CD3, CD5, CD11b and CD23. These lymphocytes were clearly of the B-cell type, as they expressed reaction with the CD19 antigen, and both kappa and lambda light-chains were expressed, indicating a polyclonal expansion of the B-lymphocyte pool (Fig. 1). Chromosome studies were carried out on lymphoid cells from peripheral blood according to standard methods. Karyotypes were described according to the International System for Human Cytogenetic Nomenclature, 1995 (13). The patient demonstrated the presence of different clones (Fig. 2, Table 1). FISH studies, using a-satellite centromeric probe from chromosome 3 (CEP 3, Vysis, Downers Grove, USA), demonstrated the presence of three Eur J Haematol 2000: 64: 344±346 Printed in UK. All rights reserved Copyright # Munksgaard 2000