From the large amount of data pertaining to a possible relationship between MHC and susceptibility to malignancies in humans, some significant findings emerge. 1. In population studies, HLA-A2 in ALL and A1 in Hodgkin's disease are observed significantly increased in frequency in comparison to the normal controls. Some significant associations with an HLA phenotype are also observed in several cancers. 2. HLA genotyping of familial cases of Hodgkin's disease, with multiplex affected sibs, lead to the conclusions that an excess of HLA identical pairs are observed among the patients. This could indicate a linkage between the susceptibility gene and the HLA region. Another linkage might exist with familial malignant melanoma fitting with a dominant mode of transmission of the trait. These facts strongly support the role of the MHC among the polyfactorial and polygenic determinism of some malignancies. The mechanisms are discussed.

In 4 cases, the probable diagnosis was that of a chronic myeloid leukaemia (CML) in a blast crisis, because of the sudden acute onset and the presence of the Ph 1 chromosome. In each case, however, there were Auer bodies in the blasts, an unusual finding in CML. Cytological and cytochemical examination led respectively to the diagnosis of an M2 acute myeloblastic leukaemia (AML), according to the FAB classification, to that of a pre-leukaemia progressing to an M2 AML, to that of a M3 promyelocyte leukaemia, with numerous monocytes and finally, in one case, the diagnosis lay between a possible acute crisis of CML with Auer bodies or an acute myelo-monocyte leukaemia. These atypical findings did not conform to the classic picture of CML and cannot be classified as such in spite of the presence of the Ph 1 chromosome. To consider them as true CML would be to run a risk of distorting the haematological evolutive and therapeutic aspects of this disease.

A case of malignant carotid body chemodectoma with neighbouring lymph nodes metastases is reported. The case is noteworthy as it was accompanied by another jugulotympanic chemodectoma. There was also hereditary component as four of the patients forebears had been operated for cervical chemodectomas. An ultrastructural study showed the characteristic secretory granules. 32 other cases of tumors of carotid body and jugular glomus with metastases are reviewed.

Sixty-six patients with chronic myelogenous leukemia, all with Philadelphia chromosome, have been studied for chromosomic abnormalities associated (CAA) to Ph', as well as for actuarial curve of survivorship. Patients dying from another disease were excluded from this study. Frequency of cells with CAA was measured and appeared strongly higher after blastic transformation than during myelocytic state; probability to be a blastic transformation is closely correlated with this frequency. On the other hand, actuarial curve of survivorship is very well represented by an exponential curve. This suggests a constant rate of death during disease evolution, for these patients without intercurrent disease. As a mean survivance after blastic transformation is very shorter than myelocytic duration, a constant rate of blastic transformation could be advanced: it explains possible occurrence of transformation as soon as preclinic state of a chronic myelogenous leukemia. Even if CAA frequency increases after blastic transformation, CAA can occur a long time before it and do not explain it: submicroscopic origin should be searched for the constant rate of blastic transformation would express the risk of a genic transformation at a constant rate during myelocytic state.

The study--on continuous cell lines or on fresh tumor cells--of chromosomes and immunoglobulins from 29 Burkitt-type lymphomas or leukemias showed a strong correlation between translocation t (2; 8) and expression of kappa light chains on the one hand, and between translocation t (8; 22) and expression of lambda chains on the other. The positions of the genes that code for these immunoglobulin chains, on chromosomes 2 and 22, respectively, suggest a precise regional localization close to the break-points observed in the translocations (2p12 and 22q11). These results should make it possible to look for and identify the DNA sequences that are implicated in the malignant transformation of these cells, using molecular biology techniques.

Gardner's syndrome, a hereditary affection of the bastoderm layers, is rarely recognized though it is seen in 8-16% of cases of colorectal polyposis. Seven cases (4 female and 3 male) of Gardner's syndrome in 3 families are presented. Six of the patients belonged to 2 families, several members of which suffered from familial polyposis; the seventh case was an isolated case of Gardner's syndrome without a family history of polyposis. Because of the high risk of malignancy in the presence of polyps, the treatment of Gardner's syndrome is identical to that of familial polyposis. Four patients underwent total colectomy and 2 simple polypectomy. One refused all treatment or monitoring. From these patients, one of the polyps excised from the rectum was found to be undergoing malignant transformation. The extracolic symptoms of this condition precede polyposis within the gut; they attract attention and thus permit early diagnosis.

A 13 year-old boy presented with Burkitt's type acute lymphoblastic leukemia (B-ALL). Studies of immune markers on his lymphoblasts suggest they have reached a fairly advanced level of differentiation with in the B-cell lineage. Presence of 1q+ and 8q- chromosomes suggest an unusual (1;8) translocation and is in agreement with current concepts concerning the frequent chromosome 8 changes in B-ALL.