Anne G. Sørensen

Cytogenetic findings in adult de novo acute myeloid leukaemia. A population-based study of 303/337 patients

Summary. During a 10‐year period (1992–2001) in the region of Southern Denmark, 337 patients aged 15 years or older (range 16–93 years, median 67 years) were diagnosed with acute myeloid leukaemia (AML). Cytogenetic analysis was carried out in 90%, of whom 53% had clonal chromosome aberrations. Some 24% and 31% had only numerical or structural abnormalities respectively. The remaining patients showed both types of abnormalities. Ploidy levels in decreasing order were: pseudodiploidy, 41%; hyperdiploidy, 32%; and hypodiploidy, 27%. Pseudodiploidy characterizes type M3 (70%) and hypodiploidy M6 (56%). Recurrent cytogenetic abnormalities – t(8;21), t(15;17) and inv(16) – were found in 3·3%, 3·3% and 2·0% of all patients respectively. Prognostically intermediate and adverse aberrations were found in 39% and 44%, respectively, of those with an abnormal karyotype. Rare recurrent aberrations were found in two patients in this material. A previously described non‐recurrent abnormality was found to be recurrent in one patient [der(20)t(11;20)(q13.2;p13)]. New, previously undescribed abnormalities were found in 41 patients. Statistically significant correlations were found between t(15;17) and young age (P < 0·001), inv(16) and young age (P < 0·006), −17 and M6 (P = 0·007), and M6 and complex karyotype with five or more unrelated aberrations (P = 0·004). We conclude that this truely population‐based cytogenetic study of adult AML showed distributions of chromosome abnormalities that differ from those described so far.

Cytogenetic findings in adult secondary acute myeloid leukemia (AML): frequency of favorable and adverse chromosomal aberrations do not differ from adult de novo AML

During a 15-year period, 161 adult patients were diagnosed with secondary acute myeloid leukemia (s-AML) in the region of Southern Denmark. In 73 patients, the AML diagnosis was preceded by myelodysplastic syndrome (MDS-AML), in 31 patients by an antecedent hematologic disease, and in 57 patients by treatment with chemotherapy and/or irradiation (t-AML). Cytogenetic analysis was carried out in 93%, of which 61% had clonal chromosome aberrations. MDS-AML correlated to a normal karyotype (P < 0.001). t-AML correlated to abnormal clones with numerical and structural aberrations (P = 0.03), five or more unrelated aberrations (P = 0.03), marker chromosomes (P = 0.006), abnormal mitoses only (P = 0.01), female sex (P < 0.001), and -7 (P = 0.006). Centromeric breakage correlated to a complex karyotype (P = 0.01). The frequencies of aberrations in s-AML patients were compared with an age-matched group of de novo AML patients diagnosed in the same area and period. In this comparison, s-AML only correlated to -7 (P = 0.02). In 42 patients, we found that MDS patients with an abnormal karyotype were more likely to show cytogenetic evolution during progression to AML than MDS patients with a normal karyotype (P = 0.01). We conclude that population-based cytogenetic studies of adult s-AML and age- and sex-matched de novo AML show comparable distributions of chromosome abnormalities.

Simple numerical chromosome aberrations characterize pituitary adenomas

Although pituitary adenomas are among the most frequent intracranial neoplasms, only very few have been cytogenetically analyzed. We have short-term cultured and karyotyped 28 consecutive pituitary adenomas (16 clinically nonfunctioning adenomas and 12 clinically functioning adenomas), finding a normal karyotype in 22, whereas 6 had clonal chromosome aberrations (5 nonfunctioning pituitary adenomas and 1 prolactinoma). The abnormal karyotypes were relatively simple. Most anomalies were numerical, with a structural rearrangement, t(6;19), being found in only one tumor. The most common aberrations were trisomy 7 (3 adenomas), trisomy 9 (2 adenomas), trisomy 12 (2 adenomas), trisomy 20 (2 adenomas), and loss and gain in 2 separate clones of one X chromosome (2 adenomas).

Chromosome Aberrations in Adult Hodgkin Disease in a Danish Population-Based Study

During a 6-year period, 31 patients with Hodgkin disease (HD) were analyzed for chromosome aberrations on lymphoid tissue. We obtained metaphases in 87% (27/31). The number of cells analyzed per case ranged from 17 to 31 (median 25), and the number of abnormal mitoses was between 1 and 17 (median 6). Chromosome aberrations were found in 59% (16/27). Numerical aberrations involved all chromosomes. The most frequently gained chromosomes were numbers 2 and 9, and the most frequently lost were numbers 10, 16, 21, 22, and X. Chromosomes most frequently involved in structural aberrations were numbers 1 and 6. The most frequent subgroups were nodular sclerosis (NS) (n = 16) and mixed cellularity (MC) (n = 10). Six NS patients and 8 patients with MC showed an abnormal clone. For the NS patients with an abnormal karyotype, 4 of 6 had a gain of chromosome 2, and all had structural aberrations of chromosome 1. Of the 6 MC patients, where a partial analysis was possible, 4 had a gain of chromosome 9, 2 had structural aberrations involving chromosome 6 and 2 of chromosome 14. In 1 case a translocation normally associated with non-Hodgkin lymphoma (NHL) was found (t[11;14]), whereas other translocations characteristic of NHL, such as t(8;14), t(14;18), and t(2;5) were not observed. A review of the literature on cytogenetic investigations in HD performed on lymphoid tissue showed that the most frequently gained or lost chromosomes were 1, 2, 5, 9, and 12 for NS and 2, 5, and 9 for MC. The most frequently affected chromosomes in structural aberrations were 1 and 6 for NS, and 1, 7, and 14 for MC. Involvement of chromosome 1, 6, and 14 in structural aberrations is characteristic of lymphoid neoplasms, as are the most frequently involved bands (1p36, 6q21-q26, 14q11, and 14q32) further supporting a B- or T-cell origin of the neoplastic cell in HD. The high hyperploidy seen in HD is not a frequent observation in NHL. Although certain chromosome aberrations seem to be characteristic of HD as opposed to NHL, specific nonrandom aberrations have yet to be identified. The rather low number of abnormal mitoses found in most HD cases underlies the importance of analyzing a large number of metaphases.

Haemophagocytic lymphohistiocytosis associated with constitutional inversion of chromosome 9

Familial haemophagocytic lymphohistiocytosis (HLH) is considered an autosomal recessive disease, although the putative gene responsible for the disease has not yet been localized. Identification of the involved gene may elucidate the pathogenesis of the disease and is essential for prenatal testing in affected families. We present an infant with HLH and constitutional inversion 9 (p23q31) in cells from bone marrow, lymphocytes and fibroblasts. The parents had normal karyotypes. It may be speculated that one of the parents was a carrier of HLH and a de novo inversion occurred in chromosome 9 from the non‐carrier parent. This would imply that the putative HLH‐related gene is located at one of the two breakpoints on chromosome 9.

A case of childhood acute myeloid leukemia associated with inversion (7)(p21q31).

We describe a case of acute myeloid leukemia in a 2 1/2-year-old boy presenting with a mediastinal tumor causing respiratory distress, and lymph node enlargement in the cervical and inguinal regions. Apart from myeloid markers CD13 and CD33, blast cells also expressed stem cell marker CD34 and megakaryocytic marker CD61. Cytogenetically, inv(7)(p21q31) was found in 9/25 and 15/25 analyzed metaphases from short-term cultures of lymph node and bone marrow cells, respectively. The patient is in continued complete remission 26 months post diagnosis. The case demonstrates that chromosome aberrations other than inv(16), t(8;21), and t(9;11) may be associated with extramedullary disease, and that not all chromosome 7 aberrations are prognostic adverse findings.