Detectable karyotypic changes have been observed in more than 50% of patients with ALL. Distinct nonrandom chromosome abnormalities have been found. Some of these can be correlated with particular parameters such as age, morphology of the blasts, lymphocyte surface markers, prognosis. Karyotype is an important independent prognostic factor in ALL, even when other well-known risk factors are considered but an abnormal clone is not always associated with a poor prognosis. Burkitt leukemia and lymphomas have been shown to present characteristic and specific translocations t(8;14) and variants t (2;8) and t(8;22). It appears that the structural change of chromosome n degree 8 involving band q24 is a consistent chromosome feature in these malignancies, and that this peculiar region on chromosome n degree 8 probably plays an important biological role in the development of these malignant proliferations. The association of cytogenetic and molecular biology techniques would allow in the near future a better understanding of the genesis and significance of chromosome anomalies in malignant blood diseases.

Chromosome banding techniques have been useful to define abnormal chromosomes in acute leukemia. The comparison between cases reported from different centers has been possible only with the acceptance of a universal system of classification and nomenclature for acute leukemia as well as for chromosomal rearrangements. Chromosomes abnormalities in acute leukemia are found in about 50 per cent of patients. They appear to be non random. Clinical, morphologic and cytogenetic findings have been correlated. Diagnosis and prognosis significance of chromosome abnormalities is of importance. The problem of normal or so called normal cells in 50 per cent of acute leukemia is set.

The carcinogenic transformation depends on the presence of particular genes, the oncogenes, which are, as a matter of fact, normal cellular genes. The oncogenic retro-viruses are mosaic genomes, transducing oncogenes in the infected cells. These genes are expressed: the product has an activity of protein kinase. The expression is increased in the transformed cells, because the oncogenes are either linked to strong viral promoters in the oncogenic viruses, or translocated in the vicinity of immunoglobulin genes in the case of Burkitt lymphoma. Moreover, there is some modifications (punctual mutations or deletions) of the primary sequence of the protein.

Two cases with chromosome 11 anomaly related to cancer are reported. The first one has a pericentric inversion (inv. p14 q12) with sympathoblastoma and Ondine's curse. The second one has a deletion (11p13) with aniridia and catalase deficiency but without Wilms tumor at two year of age. Retinoblastoma, nephroblastoma and sympathoblastoma may be related to genome modification. The mechanism of oncogenesis are discussed.

All prometaphase constitutional karyotype from 13 patients with isolated whose tumor were normal, without 11p13-p14 anomaly Catalase determination showed normal results.

Over a period of 23 years, 3 members of a family of 5 presented with 7 parathyroid adenomas (4 in the first case, 2 in the second case, 1 in the third case). Excision of each adenoma, with systematic pre-operative assessment of the remaining parathyroid tissue, led to complete clinical and laboratory cure of each episode. The delay in the appearance of recurrence was between 3 and 9 years. After reviewing the literature, the authors stress the importance, in any case of hyperparathyroidism, of routinely investigating the serum calcium levels in members of the patient's family, especially if the patient is young and if he has had several episodes or a multiglandular involvement in the one episode. The authors discuss the literature concerning recurrent familial hyperparathyroidism with endocrine polyadenomatosis and the "hypercalcaemia - hypocalciuria" syndrome.