Medullary thyroid carcinoma is a rare and sometimes hereditary disease. The tumour can be diagnosed and followed up by measuring the amounts of calcitonin it secretes. The prognosis of this cancer largely depends on an early diagnosis and treatment. From the clinical and laboratory (calcitonin assays) data recorded in our department, we have endeavoured to determine the influence of a national multidisciplinary co-operative group (GETC: French medullary study group) on the diagnosis and prognosis of this malignancy. We are able to show that the number of medullary thyroid carcinomas detected (principally in their familial forms) has increased by 141 per cent after the GETC was created. Calcitonin levels at the time of diagnosis are significantly lower (P less than 0.05) in familial cases, which reflects an early detection. The same applies to post-operative calcitonin levels (P less than 0.005), so that in the long run a better prognosis can be expected. It seems therefore that together with a better knowledge of this cancer and its detection, the setting up of a national multidisciplinary co-operative group results in a better clinical and therapeutic approach of these patients, and particularly of the familial cases of medullary thyroid carcinoma.

The case report of familial Von Recklinghausen disease, allows to remind the frequency, and the polymorphism of this affection, which is provoked by the neuro-ectodermal layer dysplasia. This case, moreover, poses a difficult problem, about the appearance of asymptomatic large optic nerves in two patients.

Report of overwhelming leukemia with meningeal involvement in a 13-year-old. Cytologic and ultrastructural examinations showed features of myelomonocytic leukemia with abnormal eosinophils. The karyotype showed pericentric inversion of chromosome 16. Although these findings establish the diagnosis of acute myelomonocytic leukemia with abnormal eosinophils (M4Eo), this case ran an exceptionally severe course and exhibited some unusual cytologic features.

We report a case of acute lymphoblastic leukemia observed in a 2 year-old girl with congenital sporadic aniridia. Cytogenetic studied did not show 11 p 13 deletion, either in leukemic cells or in peripheral lymphocytes of the propositus and both parents.

Tuberous sclerosis, classified as phakomatosis, seems to be frequent in neuropaediatric practice. Twenty-two families are reported here. A few unusual features were noted in this series, including the early appearance of the first signs, the particular features of the epileptic fits, the frequency of psychotic disorders and the frequency of inherited cases.

In chronic lymphocytic leukemia (C.L.L.) the lymphocytes have been studied with new techniques of cytology, histopathology, karyotypic analyses and immunocytology. These new patterns of B lymphocytes in C.L.L. will be very useful for the treatment, the definition of remission and the study of the origin of the monoclonal clone.

Malignant cells can be distinguished from their normal counterpart at the DNA level: they carry molecular changes which are characteristic of the tumor type or which might have some prognostic value. Amplifications and mutations of oncogenes and loss of alleles have been reported to occur in lung cancers, but their prognostic value has not yet been estimated, mainly for technical reasons: primary fresh biopsies are usually too small for molecular investigation. From 79 biopsies (50 of which were obtained by fiberoptic bronchoscopy), DNA hybridization was performed using the Southern blot technique, with myc family genes probes and a polymorphic probe located on the short arm of chromosome 3. Our study indicates that: 1) in 88% cases, enough DNA can be obtained by 3 or 4 fiberoptic bronchoscopy biopsies: from 5 to 80 micrograms DNA with an average of 25; 2) the quality of DNA is good for analysis by the Southern blot technique; 3) the loss of allele on chromosome 3 (3p 14-23) can be detected both in the small cell and in the non small cell type, but contamination of the specimens by non-tumoral tissue (based on the cytological and histological analysis of each biopsy) remains a problem for this type of study; 4) gene amplifications and rearrangements can be easily evaluated for the genes of the myc family. This pilot study shows that DNA analysis is feasible on perendoscopic biopsies. Collection and analysis of a large series of such biopsies at diagnosis is essential to define the value of DNA markers as prognostic factors in lung cancers.

The clinical, epidemiological and genetic aspects of familial paragangliomas of the head and neck are discussed in relation to 6 recent cases from two families which accounted for 2 and 4 patients respectively. Tumors of the carotid body are the most frequent. Bilaterality and association with other paragangliomas are suggestive of a hereditary disorder and should lead to investigation of the family. The establishment of a family tree will define those subjects at risk in whom systemic screening should be performed. The recent advances obtained using new imaging techniques in the diagnosis, evaluation of extension and treatment should enable treatment to be instituted at an earlier stage and thus reduce functional sequelae.

The relationships between mutations, in a general sense, and cancer are reviewed with a special emphasis on the description of hereditary tumors. These rare diseases provide good biological models to better understand cancer initiation at the molecular level. Tumors transmitted with a recessive mode are usually linked with DNA repair deficiencies. Tumors transmitted with a dominant mode are usually linked with deletions in anti-oncogene sequences.

Knowledge about genetic alterations occurring in human tumors has dramatically increased following the development of cytogenetic and molecular techniques. Various alterations have been characterized: chromosomal damages, oncogene activations, loss of genetic material. Some of those alterations, such as c-abl rearrangements in certain leukemias, are characteristic of a certain type of malignancy. However, in most tumors, no such correlation has been demonstrated. We review here the genetic alterations discovered in human malignant melanomas.

Tuberous sclerosis or Bourneville's disease is a phakomatosis with common but paucisymptomatic bone localisations. Some osseous lesions, of osteosclerotic type, can be radiologically diagnosed as primary or secondary malignant disorders. We describe a case of Bourneville's disease with bone involvement, radiologically characterized by osteosclerosis areas of the spine and the pelvis. Interestingly, bone scintiscan was normal. The absence of primary malignancy, the stability of control bone X-ray films, the clinical status and the family history, together with the pathognomonic radiological feature of the hands support the diagnosis of tuberous sclerosis with bone involvement.