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An experimental model of colonic cancer can be obtained in rodents by administration of 1-2 Dimethylhydrazine. It produces constant, reproducible lesions, ranging from simple anomalies of secretion to invasive cancers, which are identical to those observed in man. It should be noted that the rats and mice used in these experiments do not present spontaneous colonic tumours. This model has contributed to the substitution of the polyp-cancer sequence by the dysplasia-cancer sequence. All of steps of malignant transformation of the mucosa can be followed by histochemistry of the mucins, by ultrastructural examination of the basement membrane and by labeling of the sub-epithelial connective tissue with hyaluronectin. In man, it is possible to define high risk lesions prior to the appearance of polyps.

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15 stellar types breast lesions were reviewed and classified according their etiology (fibrosing adenosis, dysplasia, dystrophy, radial scar of Aschoff, fat necrosis). Radio-anatomical confrontation allowed to understand the images given by the varying appearances of the connective skeleton surrounded by adipose lobules. The authors study the diagnosis of the stellar breast lesions and recall the determinant role of connective tissue in the genesis of mammographic stellar images.

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A case of multilocular cyst of the kidney in a forty-eight old female is reported. The urography-ultrasonography association had shown the heterogeneous character of the renal tumor. The angiography and the computed tomography were alarming. The real diagnosis was established by histologic study after nephrectomy.

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The diagnostic value of mammography was evaluated retrospectively in 23 recurrent carcinomas in patients previously treated by partial mastectomy with or without adjuvant radiotherapy. Mammography established accurate diagnosis in 11 of the 23 patients. Mammography should always be performed in addition to clinical and cytological examinations and results must be evaluated jointly. Confrontation of these three investigations may be inconclusive as a result of changes produced by radiotherapy or surgery. The authors recall the necessity of surgical control of any nodular lesion developed in the area of the initial operation, particularly during the first three years.

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The authors studied eleven cases of Fibrosing Adenosis of the breast. If the clinical findings and radiologic examination evoke this diagnosis only a histological proof is sure. The difficulties in histological diagnosis, the problems of the histogenesis of fibrosing adenosis are emphasized. The authors recall the excellent prognosis of fibrosing adenosis.

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Twenty-eight rats were given weekly injections of 1,2-dimethylhydrazine (DMH) for periods of 1-10 weeks. The preneoplastic changes occurring in the descending colon were monitored by transmission electron microscopy. Marked uniformity was observed in the time period of lesion development in the colon induced by the carcinogen especially at the epithelialstromal junction in preneoplastic lesions. Little changes were observed after 3 weeks treatment with the DMH. The greatest changes occurred after 6 weeks treatment, resulting in epithelium and mesenchyme. It has been confirmed that 3 weeks treatment with DMH is subcarcinogenic, whereas 10 weeks treatment results in a high incidence of tumors. These findings are compatible with the hypothesis that a carcinogen may act by inducing alterations in a small number of enterocytes and that colonic tumors arise through stepwise evolutional changes in these cells.

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1-2 dimethylhydrazine was injected subcutaneously on a weekly basis of 15 mg/kg, during periods ranging from one to twenty-eight weeks into five hundred Wistar rats. Glandular-mucin depletion appears as early as the second injection (sulfomucins disappear). From the sixth week, one observes dysplasia; if the animals are allowed to survive for a longer period all will develop colonic carcinomas, which were found mainly in the left colon. This dysplasia, which is first mild, then moderate, is finally severe in rat mucosa or in the area of polyps. Dysplastic polyps become less frequent when carcinomas increase in number and in size. The average length of survival after cessation of the exposure is inversely proportional to the total dose administered. The glandular mucin depletion-dysplasia-carcinoma sequence characterizes the types of formation of 1-2 DMH induced colonic carcinomas. One of the striking features is the early appearance of this sequence.

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We studied various tumours of the nervous system by the immunofluorescence technique using an anti-brain specific alpha 2 glycoprotein antiserum (anti-NSA3 antiserum). We found the antigen in 24/27 astrocytomas and 4/4 oligodendrogliomas but in none of the 8 meningiomas tested. There was an identity between the astrocytoma/oligodendroglioma antigen and that of normal brain as shown by the immunoprecipitation technique. By the immunofluorescence technique using inhibition of the antiserum we demonstrated that the tumour antigen is devoid of some specific nervous system determinants present in normal brain.

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The authors summarize the difficulties in diagnosis some tumour-like lesions or digestive tumours. They rely upon thirty years experience in digestive pathology and upon a survey of relevant literature. They recall the difficulties arising from the inflammatory tumour-like lesions (infiltrating sclerosis or granulomas, colitis cystica profunda, inflammatory polyps). They mention the circumstances which bring about errors or incomplete diagnosis among these very tumours. Some difficulties are due to the circumstances in which these tumours appear : the digestive cancers of the child, the assocations of some family cancers (the ill-forming tumours and the dysembryoplasic cancers, and lastly the connections that exist between some inflammatory or dystrophic diseases and tumours. Other difficulties depend upon the topography or the tumorous structure. Paneth-cell carcinomas, goblet cell carcinoid are chosen as instances among epithelial tumours. In the group of non-epithelial tumours, digestive localizations of angiomatosis and of lymphomatosis may cause errors. Likewise this can be applied to some secondary digestive tumours. Regarding these difficulties, the authors stress the necessity of a close cooperation between gastro-enterologists, surgeons and pathologists. They also stress the strict observance of techniques in fixation and preparation of specimens and biopsies, and also the necessity of completing, if need be, the habitual microscopy through more elaborate explorations (histochemistry, electron microscopy...).

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Anti-NSA3 antiserum was found to react with many kinds of benign and malignant tumours, as well as foetal skin and intestinal extracts. The corresponding antigens isolated from nervous tissue, benign breast adenoma, and a fibrosarcoma were compared. Immunoprecipitation cannot distinguish between these antigens, and their amino-acid contents were comparable. However, immuno-absorption identified an antigenic determinant that was confined to nervous tissue. Indirect immunofluorescence further confirmed the validity of the concept of a nervous form vs a mesenchymal form of the antigen. Furthermore, immunofluorescence enabled the localization of the antigen found in non-nervous tissue to mesenchyme (mesenchyme-associated antigen: MAA), whether the mesenchymal tissue be normal (foetal organs), tumoral (fibrosarcoma) or reactional (connective-tissue stroma of epithelial tumours).

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An overall survey of the transitional epithelium of the bladder and its carcinomas. This study is based upon the recent literature, in particular the considerable contribution of scanner electron microscopy. a) The transitional epithelium has the reputation of having a simple structure and even behaviour. In fact, it is complex with highly specialised surface cells. It has marked powers of regeneration after aggressions of various types. b) Tumours of the transitional epithelium are defined in relation to rupture of the basal lamina. Invasive carcinomas are classified according to their histological stage of penetration, their pure or partially metaplasic type and their degree defined according to the criteria of Broders. There exists a correlation between these three types of evaluation. Non-invasive carcinomas are either papillary--putting into question the reality of benign bladder papilloma--or flat mucosal and then often associated closely or at a distance with an invasive carcinoma. c) Abnormal regeneration, dysplasia or hyperplasia as a result of aggressions of different types or developing in isolation represent a high risk histologically, implying the need for careful follow-up and surveillance. d) Histopathological study of urothelial or transitional tumours is simple in operative specimens but difficult in biopsies. It requires close cooperation between surgeons and pathologists to ensure correct orientation of the fragments.

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An antiserum raised in Rabbits against brain glycoprotein precipitated an identical antigen in faetal dermis and intestine extracts, and also in non nervous tumors (breast adenocarcinomas and adenofibromas, ovarian cystadenoma, gastric and colonic adenocarcinomas, hepatomas, malignant melanomas, rhabdomvosarcoma, fibrosarcomas). By the indirect immunofluorescence technique, this antigen was always found associated with the mesenchymal proliferation, either malignant (fibrosarcoma) or reactive (fibrous stroma reaction of carcinomas).

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Absence of GFA in established cell lines from glioblastomas promped us to look for this protein from the first replication of malignant cells in vitro and in following subcultrues. Our results show that GFA disappeared during the first twelve replications, often before the fifth replication. No correlation was observed with a morphological transformation of the cells.

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100 Wistar rats, belonging to a series of 500 animals, were treated with increasing doses and for increasing periods of time with 1,2-dimethylhydrazine. A previous study has shown that tumors begin to appear only after the 19th week. Before this period there are abnormalities of mucin secretion (by the 2nd week), and then there are dysplasic lesions (after the 4th week). The ultrastructure study, done before the 19th week ("pretumor" phase) confirms some previous observations (increase in the zone of mitosis, secretory changes, mutation producing effects). These features are reminiscent of the histochemical characteristics of the human foetal colon. They show an epitheliomesenchymatous disorganisation unrelated to inflammation. There are abnormally early changes in the vasculature, there is loss of the (epithelial) coat, there is dissociation of the basal membrane and abnormal connections between it and the epithelial cells, collagen and fibroblasts; all this represents a disorganisation of the regeneration system of the colon mucosa. This loss of equilibrium between the parenchyma and the mesenchyma may represent a factor favoring excessive and disorganised growth of the mucosa.

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The authors poisoned 500 female Wistar rats with a dialy dose of 15 mg/kg, The total dose ranged from 15 mg/kg to 420 mg/kg, according to the group. The animals were either killed when the dose defined for each group and been reached, or allowed to live. In a first series of 6 groups (120 animals), the following facts were noted: tumours deeveloped in all animals left alive, after 28 weeks (total dose of 1/2 D.M.H. = 420 MG/KG). Changes in the mucosa were seen from the 40th day on with, in the descending colon, a punctate abnormality involving two or three glandular tubes, in general at the summit of the folds. This abnormality consisted of basophilia of the upper part of the tubes, with a loss of mucus secretion. All transitional stages were seen between this lesion, hyperplasia of the apex of the tubes, the formation of "polyp seeds" and the appearance of polyps. Carcinomas most frequently developed in polyps but sometimes in flat mucosa. In the ascending colon, changes in mucosecretion were seen after a similar time delay at the base of the glandular crypts.

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