Congenital dyserthropoietic anaemia other than type I to III with a peculiar erythroblastic morphology.

Here, we report the case of a child who, since birth, showed persistent macrocytosis and elevated mean corpuscular volume of the erythrocytes. Bone marrow biopsy revealed gross disorganisation of the erythroblastic series both at the light and electron microscopic examination, with complete absence of dysplastic features in the granulocytic and megakaryocytic series. Common causes of macrocytosis were excluded. The spectrum of morphological findings were not consistent with any of the classical types of congenital dyserythropoietic anaemias (CDAs) and serological findings of CDA type II were absent. The most outstanding feature was a marked irregularity of the nuclear outline of the late erythroblasts that presented thick-ending finger-like projections. The combination of macrocytosis without anaemia and these morphologic erythroblastic changes have not been previously reported in the setting of classical and variant forms of CDAs.

New t(11;12)(q12;q11) characterized by RxFISH in a patient with T-cell large granular lymphocyte leukemia.

Chromosomal abnormalities in patients with large granular lymphocyte leukemia (LGLL) are rare. Herein we present a novel cytogenetic abnormality t(11;12)(q12;q11) in a patient with LGLL identified by cross-species color banding (RxFISH). The application of RxFISH allowed the rapid and easy identification of a chromosome rearrangement that was not recognized by conventional cytogenetics. Therefore, RxFISH is a suitable complement to, but not a replacement for, conventional cytogenetics.

Usefulness and reproducibility of cytomorphologic evaluations to differentiate myeloma from monoclonal gammopathies of unknown significance.

We attempted to differentiate monoclonal gammopathies of unknown significance (MGUS) and multiple myeloma (MM) on morphologic grounds and to determine interobserver reproducibility of the differentiation. Cytologists blindly evaluated bone marrow smears from 154 patients with bone marrow plasmacytosis for the proportion of plasma cells with predefined cellular atypias. The single morphologic characteristic that most strongly differentiated MM from MGUS was the presence of nucleoli. The percentage of plasma cells, cytoplasmic contour irregularities, and anisocytosis also predicted a diagnosis of myeloma in multivariate analysis. Six cytologists independently evaluated 68 consecutive cases to determine sensitivity and specificity of these cytomorphologic features. The interobserver coefficient of variation for the plasma cell count was 33%. On consideration of the diagnosis, 36 of 41 MGUS cases and all 24 cases of myeloma were classified correctly. The use of a predesigned score system did not present such a bias, although it did not improve overall efficiency. The plasma cell count is the most predictive characteristic of myeloma from a cytologic viewpoint, but the interobserver variability is high. Interobserver variability is also high in the assessment of morphologic atypia, and atypical traits are not uncommon in plasma cells in MGUS.

Splenic marginal zone B-cell lymphomas: two cytogenetic subtypes, one with gain of 3q and the other with loss of 7q.

BACKGROUND AND OBJECTIVES: Splenic marginal zone B-cell lymphoma (SMZBCL) has clinical, immunophenotypic and histologic features distinct from other B-cell malignancies, but few chromosome studies have been previously reported. In the present study we performed conventional cytogenetics and in situ hybridization studies in 47 patients with SMZBCL. DESIGN AND METHODS: We studied 47 cases of splenic marginal zone B-cell lymphoma combining conventional cytogenetics and in situ hybridization (ISH) techniques using centromeric probes (chromosomes 3 and 12), locus specific probes (7q31 and 17p13) and cross-species color banding fluorescent ISH probes (RxFISH). The diagnosis of SMZBCL was ascertained in all cases after studying, morphologically and immunologically, peripheral blood and splenectomy specimens. RESULTS: A clonal chromosome abnormality detected by conventional cytogenetics and/or FISH was found in 33/47 patients (70%) being identified in 18 (18/33, 55%) as a complex abnormality. The most frequently recurrent abnormalities were: gain of 3q (10 cases), del(7q) (12 cases), and involvement of chromosomes 1, 8 and 14. No patient showed translocation t(11;14) (q13;q32) or t(14;18) (q21;q32). Trisomy 3 was detected in eight cases (8/47, 17%). Two novel cytogenetic abnormalities involving 14q32, t(6;14)(p12;q32) and t(10;14) (q24;q32) were reported. Deletion of 17p13 (P53) was observed by FISH in one case. Only one patient showed a gain of 3q or trisomy 3 and deletion 7q in the same karyotype. INTERPRETATION AND CONCLUSIONS: Our findings support the interpretation that two forms of SMZBCL could be considered, one with gain of 3q and the other with deletions at 7q.

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.

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.

Application of cross-species color banding (RxFISH) in the study of T-prolymphocytic leukemia.

BACKGROUND AND OBJECTIVE: Cross-species color banding (RxFISH) is a new FISH technology based on the use of differentially labeled gibbon chromosome probes to obtain a specific color banding pattern for each human chromosome. The aim of the study was to test the RxFISH technique for better characterization of complex karyotypes in patients with T-prolymphocytic leukemia (T-PLL). DESIGN AND METHODS: The study evaluated the cross-species color banding technique in four patients affected with T-PLL previously studied by conventional cytogenetics. RESULTS: All patients showed an abnormal karyotype and three of them had a complex karyotype. The involvement of 14q11 in all four cases, the gain of 8q in three cases and a loss of chromosome 10, 15 and 17 and a gain of chromosome 21 in two cases were noted. The RxFISH technique identified from 2 to 7 not previously recognized aberrations per case and confirmed the inv(14)(q11q32). INTERPRETATION AND CONCLUSIONS: To our knowledge, this is the first application of RxFISH to characterize chromosomal rearrangements in T-cell neoplasms. RxFISH gave rapid and easy identification of chromosome rearrangements that were difficult to recognize by conventional cytogenetics. Using this new technology we identified 15 rearrangements not detected by conventional cytogenetics.

Incidence, characterization and prognostic significance of chromosomal abnormalities in 640 patients with primary myelodysplastic syndromes. Grupo Cooperativo Español de Citogenética Hematológica.

Recently, a consensus International Prognostic Scoring System (IPSS) for predicting outcome and planning therapy in the myelodysplastic syndromes (MDS) has been developed. However, the intermediate-risk cytogenetic subgroup defined by the IPSS includes a miscellaneous number of different single abnormalities for which real prognosis at present is uncertain. The main aims of this study were to evaluate in an independent series the prognostic value of the IPSS and to identify chromosomal abnormalities with a previously unrecognized good or poor prognosis in 640 patients. In univariate analyses, cases with single 1q abnormalities experienced poor survival, whereas those with trisomy 8 had a higher risk of acute leukaemic transformation than the remaining patients (P = 0.004 and P = 0.009 respectively). Patients with single del(12p) had a similar survival to patients with a normal karyotype and showed some trend for a better survival than other cases belonging to the IPSS intermediate-risk cytogenetic subgroup (P = 0.045). Multivariate analyses demonstrated that IPSS cytogenetic prognostic subgroup, proportion of bone marrow blasts and haemoglobin level were the main prognostic factors for survival, and the first two characteristics and platelet count were the best predictors of acute leukaemic transformation risk. A large international co-operative study should be carried out to clarify these findings.

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.