Tanizawa RS, Azevedo Neto RS, Kumeda CA, Leal AM, Ferreira PB, Velloso ED The median age of patients with previous aplasia was 24 years (range: 15-61), six (54%) were male and the latency period until developing secondary MN was 97 months. Of the other 31 patients, median age was 60 years (range: 4-88), 16 (51.6%) were male and the median latency period was 76 months. Cytogenetic characteristics This study includes cytogenetic studies of 38 patients performed when secondary MDS/MN was suspected. In six cases, no cell growth was achieved; clonal abnormalities were 428 Rev Bras Hematol Hemoter. 2011;33(6):425-31