ABSTRACT Introduction: The myelodysplastic syndromes (MDS) are a group of heterogeneous clonal hematopoietic stem cell disorders that results in peripheral blood (PB) cytopenias and bone marrow (BM) dysplasia. Dysplasia is the hallmark of the disorder, and must exceed the threshold of 10%. Conventional karyotype (KT) has a role in the classification and prognostication of subtypes. In daily practice, many cases are diagnosed in face of exuberant clinical complains, but cases with dismal evidences pose real difficulties to definitively conclude the case. Material and methods: The objective of this study is to detect cases in which no morphology evidence of dysplasia or increased blasts were observed but KT was decisive for MDS diagnosis. 666 cases were admitted to rule out MDS. Results: There were found 5 (0.75%) cases who presented no evident dysplasia morphology or whose dysplasia was borderline but the karyotype was decisive because showed clonal evidence. The karyotype was: case 1: 46,XY,del(5q)(q13q33),del(11)(q13q23)[7]/46,XY[13]; case 2: 46,XX,del(11)(q21q23)[20]; case 3: 46,XX,del(7)(q22q34)[4]/46,XX[8]; case 4: 47,XX,del(5)(q13q33),+mar[12]/46,XX[8] and case 5: 46,XXt(2;11)(p21;q24),del(4)(?q25),del(21)(q22)[14]/46,XX[6]. Conclusion: Patients with cytopenia and insufficient or borderline evidence of dysplasia may experience a long journey before a MDS diagnosis is made. Cytogenetics studies may abbreviate this pathway when clonal aberrations considered presumptive of MDS are detected. This study shows that karyotype should still be considered as a diagnostic tool.

INTRODUÇÃO: A leucemia linfocítica crônica (LLC) é doença neoplásica caracterizada pelo acúmulo de linfócitos B maduros CD 5, CD 19 e CD 23 positivos. Alterações cromossômicas têm sido descritas pela citogenética clássica em 30% a 50% dos casos de LLC. OBJETIVO: O objetivo do presente trabalho é demonstrar as alterações de cariótipo observadas em pacientes com LLC em nosso meio. PROCEDIMENTOS: Foram selecionados 18 casos de nosso arquivo, avaliados no período de quatro anos, com LLC diagnosticada com base nos achados morfológicos e imunofenotípicos. Havia 13 homens e cinco mulheres, uma relação de 2,6:1, com mediana de 63 anos. RESULTADOS: Foram detectadas alterações de cariótipo em 39% dos casos (7/18). CONCLUSÕES: O cariótipo permitiu a identificação de diferentes clones em um grupo homogêneo de LLC sob os pontos de vista morfológico e imunofenotípico, demonstrando que as alterações genéticas são indicativas de comportamento biológico diferente.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is a neoplasic disorder characterized by the accumulation of mature B lymphocytes CD 5, CD 19 and CD 23 positive. Chromosomal abnormalities have been described in 30% to 50% of the cases by conventional cytogenetics. OBJECTIVE: The objective of the present work was to describe chromosomal abnormalities detected in Brazilian CLL patients. METHODS: Eighteen cases with CLL selected from our files, in a 4 year period, were studied. The diagnosis was based on morphology and immunophenotype. There were 13 men and 5 women, a 2.6:1 ratio, with 63 median age. RESULTS: Chromosomal abnormalities were detected in 39% of the cases (7/18). CONCLUSION: The karyotype allowed the identification of different clones in a heterogenous CLL group under morphology and immunophenotype point of view demonstrating that genetic alterations are indicative of a different biological behavior.

The Philadelphia chromosome is observed in 5% of pediatric acute lymphocytic leukemia (ALL) and in 25% to 50% of adult ALL cases, and is associated with poor prognosis. Double Ph in a hyperdiploid karyotype is common in chronic myeloid leukemia (CML), but rarely found in ALL. We report here the case of a girl diagnosed with ALL at 7 years of age. After treatment with the pediatric protocol BFM 83 for ALL, she stayed in continuous complete remission for nine years. At age 19, she was re-admitted with a white blood cell count of 6.8 x 10(9)/L with 3% blasts, and a platelet count of 65 x 109/L. Bone marrow aspirate showed 92.6% lymphoid blast cells, and chromosome analysis after G-banding revealed the karyotype 51,XX,+?5,t(9;22)(q34.1;q11.2),+16,+20,+21,+der(22)t(9;22)(q34.1;q11.2) [10]/46,XX[1]. FISH analysis for the BCR/ABL fusion showed 56% of interphase cells with two fusion signals, 30% with one, and 6% with three. Double Ph is rare in relapsed leukemia, and the possibility of secondary leukemia cannot be ruled out.