Karyotypic and fluorescent in-situ hybridization study of the centromere of chromosome 7 in secondary myeloid neoplasms observed by conventional karyotyping in 25/32 (78.1%) cases. FISH investigations (Table 2) for chromosome 7 monosomy were carried out in 11 patients; two (18.2%) were positive (Patients 1 and 25). Altogether, the clonal abnormalities detected by conventional karyotyping and FISH accounted for 27/32 (84.4%) of the cases. Monosomy 7 was observed in 10/27 (37%), complex karyotypes in 12/27 (44.4%) and other abnormalities in 5/27 (18.5%) including deletion of the long arm of chromosome 7, chromosome 8 tetrasomy, t(3;21) and structural alterations involving chromosomes 1 and 21 (Figure 1). The frequency of unbalanced abnormalities was 26/27 (96.3%); a single case presented a balanced abnormality. Monosomy 7 was more prevalent in patients with secondary MN after AA (66.6%), whereas in the other cases the incidence of complex karyotypes was higher (52.2%). The description of the karyotypes according to the ISCN 2009 and the classification of the abnormalities are shown in Table 2. Figure 2 exemplifies a complex karyotype, Figure 3 shows a karyotype with a balanced translocation and Figure 4 is a FISH image showing a nucleus with monosomy 7. Figure 1 – Incidence of chromosome abnormalities (%) in secondary myeloid neoplasms (n = 27) Figure 2 – Therapy-related complex karyotype (Patient 14) showing del(5q), trisomy 8 and del(13q). The therapy for follicular lymphoma (previous disease) included cyclophosphamide and fludarabine phosphate Rev Bras Hematol Hemoter. 2011;33(6):425-31 Figure 3 – Therapy-related anomaly (Patient 9) showing t(3;21) (q22;q26). The therapy for plasma cell myeloma (previous disease) included melphalan Figure 4 – FISH study using centromeric probe for chromosome 7. Therapy-related abnormality (Patient 25) one interphase cell (only one green signal) demonstrating monosomy 7. The therapy for rhabdomyosarcoma (previous disease) included cyclophosphamide, etoposide, doxorubicin and carboplatin. Cytogenetics and prognosis The median overall survival of the 42 patients was 6 months; a little shorter (5.7 months) when the date of HSCT, a procedure used for eight patients, was delayed. A normal cytogenetic result was associated with better survival (no median value was reached in this study) compared to an abnormal cytogenetic result with 5 months median survival (p-value = 0.03 – Figure 5). A slight tendency of poorer survival was observed when complex karyotypes was compared with other cytogenetic abnormalities (p-value = 0.057). There was no significant difference between patients with chromosome 7 monosomy 429