The PFT cell line was established in 1969 from diploid cells of the inner lining of a uterine tube of a 2 year-old sow and has been continuously subcultured more than 500 times over a decade. Three chromosomal rearrangements have occurred during this time. The first translocation was shown at the 100th passage with the concomitant and spontaneous release of an endogeneous type C virus. The second translocation was observed at the 290th passage along with the appearance of gap junctions and the induction of malignant tumors in athymic nude mice following the inoculation of PFT cells. The third translocation was found towards the 470th passage with the simultaneous appearance of annulate lamellae. Since the translocations were accompanied by the spontaneous release of a retrovirus and then by malignancy of PFT cells when inoculated in athymic nude mice, it is likely that the chromosomal abnormalities are associated with the viral carcinogenesis of the cell line. The third translocation appears to confirm the perenniality of the multistep evolution hypothesis of malignancy.

Genetic susceptibility (HLA types), clinical and pathological findings, amount of acetylcholine receptor antibodies and T lymphocyte subpopulations were studied in 63 patients with Myasthenia Gravis (MG). The frequency of HLA-DR5 was increased among patients (0.50 versus 0.23 in controls, pc less than 0.01, relative risk 3.3) and that of HLA-DR3 previously described as associated with MG was slightly increased (0.31 versus 0.20 in controls). The relative frequencies of two T cell subpopulations (T4 helper and T8 suppressor/cytotoxic lymphocytes) were normal in HLA-DR5 positive patients while the ratio T4/T8 was increased in other MG patients, who were HLA-DR3 (p less than 0.005). The high rate was due to an increase in the absolute number of T4 lymphocytes (p less than 0.001). HLA-DR3 patients were mostly women with early onset of a severe form of the disease, marked by the presence of thymic follicular lymphoid hyperplasia. A third genetic susceptibility to this disease was recently described in patients treated with D-penicillamine, the antigenic frequency of HLA-Bw35, DR1 is significantly increased. These 3 types of association between HLA and myasthenia gravis can be related to three different physiopathological mechanisms: the first two are probably linked to individual immunity (inductor/suppressor disequilibrium), in the third association, the mechanism is immunopharmacological.

A patient with Ph1 positive chronic myeloid leukemia developed accelerated phase with cytological abnormalities of platelets and megakaryocytes, and persistence of a high platelet count, after the failure of a course of intensive chemotherapy. During this phase, the karyotype analysis revealed two different Ph1 positive clones: one with a pericentric inversion of chromosome 3, the other with the same abnormality and a paracentric inversion of the second chromosome 3. Cases of acute leukemia with normal thrombopoiesis and abnormalities of chromosome 3, especially paracentric inversion, have already been reported. The significance of this association is discussed.

Secondary bone sarcomas are frequent among children who have been treated previously for a retinoblastoma. The main point is that these bone sarcoma occur almost always after a bilateral retinoblastoma and more often in the irradiated area; from these, the classical concept of "radiocancer" was generally admitted. However, since many authors reported bone sarcomas occurring in a different location from the irradiated area, radiotherapy cannot be by itself the causative factor of these secondary bone sarcomas. Therefore the genetical factor is probably one of the predisposing factor. The authors report 6 cases of bone sarcomas with a review of the literature of bone sarcomas occurring in the irradiated field or not, for children "cured" of retinoblastoma.

The authors report their experience of three cases of carotid corpuscle tumors: two are bilateral and pertaining to the same family, one of them is associated with a bilateral tympano-jugular glomus. First they review the epidemiology and definitions of such tumors and then they develop the various clinical aspects and differential diagnosis of these tumors. They insist on the necessity of a CT scan examination and of an angiography. They give their experience of the preoperative embolization of the tumour vessels. They expose various aspects of the surgical technique, pointing out the interest of a large access, the need of a regular surgery and the necessary collaboration between head and neck surgeons and vascular surgeons. Finally they discuss the opportuneness to operate bilateral glomic tumors.

The presence of a rearrangement of the proto-oncogene c-myc was investigated in the DNA of fresh cells isolated from the blood of two patients with Burkitt's leukemia (L3), and from the node biopsy of a patient with Burkitt's lymphoma. Both samples from the L3 leukemia patients had the characteristic t(8;14) translocation, while the lymphoma specimen presented no abnormality of chromosome 8. Only one of the leukemic DNA's presented a rearranged c-myc pattern, with the breakpoint region located between the first and the second exon. The c-myc pattern of the two other patients appeared normal. The finding of a rearranged c-myc oncogene in fresh cells from a Burkitt's leukemia is direct evidence for the implication of c-myc in the disease whereas most of the rearrangements previously described have been found in cell lines established in culture.

Authors summarized the chromosomal anomalies known in Leukemias Lymphomas and solid tumors. Break points are not random but corresponded to oncogenes localizations. A fondamental role in cancerogenesis is played by oncogenes.

In 80% of cases, the histological pattern of medullary carcinoma is well known. Further investigations are needed in atypical cases, such as immunohistochemistry and electronic microscopy. The authors emphasized different diagnostic methods with a special mention for cytological analysis.

Cowden's disease is a phacomatosis (multiple hamartomas), which is a familial, hereditary, dominant autosomal affection presenting as typical buccolabial mucocutaneous lesions associated with digestive tract polyps. Differential diagnosis of the predominantly digestive form of the disease is polyposis. A new case of this rare disorder is reported, only 62 cases being documented in literature.

Five members of one family had been operated on for primary hyperparathyroidism. One of them also had Cushing's disease (i.e. pituitary tumor). An association between familial hyperparathyroidism and Cushing's disease is quite unusual. Such a combination of rare diseases is not fortuitous though; it probably is but a special type of multiple endocrine neoplasia.

On the basis of a personal case and a review of the literature, the authors describe the particular features of the association of neurofibromatosis and pregnancy. With the exception of a few severe forms of the disease, pregnancy is possible in the majority of patients with neurofibromatosis, although there is a risk of hypertension of pregnancy. The rate of abortion is a little higher than in the general population.