[Dysplasia and cancer].

Problems of morphological features and nature of dysplasia and its role in blastomogenesis are discussed. It is pointed out that the term "dysplasia" is used in modern pathology to designate various processes including disembryogenetic, adaptive-hyperplastic and pretumourous ones. The necessity of a uniform interpretation of this term is underlined, its definition is given and it is suggested to distinguish between metaplastic processes and dysplasia.

[Tumors and tumor-like lesions in children (based on 5 years' biopsy data)].

The material examined allows the authors to admit that for the diagnosis of children tumours the morphological criteria recommended by WHO classifications should be used until the specific histological classification of children neoplasms is worked out. This approach will permit the experts from different hospitals to come to the unified opinion as to the evaluation of the children tumour morphology, will make comparable the results of their studies which will create the possibility for complex investigations and will facilitate the elaboration of specific classification of tumours in this age group.

[Pathology of mitosis in clinical oncomorphology].

The results of studies of the mitosis pathology performed for many years on the material of tumour biopsies are summarized. It is shown that the determination of the tissue mitotic regimen is a theoretically founded method of cytological analysis that gives the pathologist a possibility for a more objective morphological diagnostics of pretumourous conditions and malignant tumours. The availability of this method makes it possible to recommend its wide use in the clinical oncomorphology provided the conditions assuring the minimal alteration of dividing cells (early fixation and cutting of the material) are strictly respected.

[Histogenetic and morphogenetic problems of pleomorphic adenoma of the salivary glands].

Electron microscopic examinations of pleomorphic adenoma tissue showed epithelial and myoepithelial cell elements to take part in morphogenesis of both epithelial and "mesenchymal" zones. The epithelial component of pleomorphic adenoma is represented by cells showing signs of structural-functional differentiation of the squamous epithelium,, epithelium of terminal secretory parts of the salivary gland, and myoepithelial cells. The "mesenchymal" component is also represented by myoepithelial and epithelial cells.

[Modern clinical oncomorphology].

The concept of present-day oncomorphology and the perspectives of its development are discussed. The role of morphological research in oncological clinic and trends in improvement of tumor diagnostic procedures are outlined. The review specifies the number of the studies and their objects.

[Kidney cancer (modern concepts of its histogenesis, nomenclature and classification)].

Using their own and literature data the authors recommend that malignant epithelial renal tumors be termed as "renal carcinoma" or "renal cell carcinoma". The term "hypernephroid carcinoma" which is of only historical importance may be used as a synonym of clear cell renal carcinoma. Designation of all forms of renal carcinoma by the general term "renal adenocarcinoma" does not reflect all the diversity of structure of malignant epithelial renal tumors.

[Pathomorphosis of tumors (proceedings)].

The results of morphologicl examinations of some soft tissue sarcomas, osteogenic sarcoma, and lymphogranulomatosis after radiation therapy are presented. Morphological changes developing after radiation and drug therapy of tumors are similar, only the extent of their intensity, vascular reaction, and changes in the adjacent tissues are different. Five cases of acute leukemia developing in patients with lymphogranulomatosis in the presence of long-term cytostatic therapy are described.

[Histogenesis of stomach cancer].

A conclusion on histogenetic unity of various structural variants of carcinoma of the stomach is drawn from the analysis of the data from literature and the own observations referring to light and electron microscopy and histochemistry of precancer alterations of the gastric mucosa and carcinoma of the stomach as well as the clinical pattern and prognosis of carcinoma of the stomach depending on the morphological structure of the tumour. All the variety of morphological and functional properties of tumours depends on the level and direction of differentiation of carcinoma cells.

[Immunodiffusion analysis of embryonic prealbumin in a tumorous tissue extract].

By immunodiffusion analysis the presence of embryonal prealbumin (EPA) in extracts of different tumors has been studied. EPA is most frequently detected in extracts of bone tumors (75.0%) with the titre up to 1 : 256 and in tumors of soft tissues (74.

[Electron microscopy in the differential diagnosis and prognostic evaluation of muscle tissue tumors].

The ultrastructure of striated and smooth muscle tumors of man was studied. A set of features indicating the histological origin of these tumors was established. The most informative feature for tumors of both groups is the presence of fragments of specific microfibrillar apparatus.

[Histological classification of stomach cancer and its prognostic value].

The morphology of stomach carcinoma was analysed in relation to the longevity of the patients after a radical operation for 1958--1967 (513 observations). The highest prognostic importance was found to belong to such factors as the presence of metastases in the perigastral lymph nodes, the depth of the tumour outgrowth through the stomach wall, the pattern of the tumour growth in relation to the surrounding tissue (pushing back or infiltrating), mucus formation in the tumour, the reaction of the tumour stroma and the surrounding tissue in the form of infiltration with lymphoid or plasma cells. The histological form of the tumour by itself as well as the degree of its structural differentiation are of little value for the prognosis.

[Histogenesis and pathoanatomical diagnosis of human tumors in the light of electron microscopic data].

On the basis of the analysis of the materials obtained in the Pathological Anatomy Department of the Oncological Research Center of the USSR AMS and data from literature the author demonstrates the importance of the electron microscopic examinations for the investigation of histo- and morphogenesis of tumours and for their practical diagnosis.

[A comparative immunofluorescent study of carcino-embryonic antigen in pseudomucinous cystoma of the ovary and adenocarcinoma of the large intestine].

The indirect method of immunofluorescent analysis was applied to the study of the localization of the carcinoembryonic antigen (CEA) in pseudomucinous cystoma of the ovary and adenocarcinoma of the large intestine. CEA proved to be concentrated in the membranes and the basal part of the epithelial cells both in the pseudomucinous cystoma of the ovary and in the carcinoma of the large intestine.