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Pulmonary carcinoid tumors are considered low grade malignant tumors, arising from neuroendocrine cells from bronchial mucosa. The small cell proliferation is arranged in small nests or trabeculae, the nuclei are round to oval with finely dispersed chromatin, indistinct nucleoli, small amount of cytoplasm, indistinct borders. Problems of differential diagnosis could appear in distinction with others malignancies like adenocarcinomas, squamous cell carcinomas, lymphomas and others neuroendocrine tumors, especially in the different prognosis and therapeutic approach. We described 15 cases of pulmonary carcinoid tumors diagnosticated by morphologic and immunohistochemical methods.

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The authors present the histopathologic aspects in a case of strumal carcinoid (struma ovarii and carcinoid) with 5 years clinical follow-up. The differential diagnosis difficulties between a thyroid carcinoma developed within a struma ovarii and various patterns of carcinoid are also stressed.

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The effect of colchicine was followed up in the superior cervical ganglion of rats. An increase was observed in the number of autophagocytosis vacuoles in the neurons, especially three and four hours after the intraperitoneal injection of colchicine (0.05 mg/100 g.b.w.). These vacuoles presented very various ultrastructural characters due to their different content and stage of degradation. Their high number is explained by the action of colchicine upon cytoplasmic microtubules, the secondary inhibition of the intracellular movement, and the blockage or reduction of the fusion of primary lysosomes with the autophagic vacuoles, which are continuously formed in the neuron cytoplasms, as well as in other cells.

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The electronmicroscopic investigation of five lung tumors histodiagnosed as macrocellular carcinomas showed the ultrastructural monomorphism of large, variedly shaped neoplastic cells, lack of intercellular junctions, voluminous nuclei with many indentations of nuclear membrane, dispersed euchromatin, large and multiple nucleoli, and nuclear bodies. A reduced number of cytoplasmic organelles was characteristic for these cells, represented mainly by mitochondria, rare rough endoplasmic reticulum, free ribosomes rare Golgi vesicles and flattened tubules, and a various amount of tonofilaments. These features characterized the poorly differentiated proliferation forming these tumors. The elements of differential diagnosis from other poorly differentiated lung tumors (epidermoid and cylindrocubic) are discussed, allowing the consideration of this proliferation type with repressed differentiation and maturation as a real one in the framework of lung carcinomas.

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Five epidermoid (squamous cell) carcinomas of the lung histopathologically diagnosed were ultrastructurally analysed; special attention was given to the poorly differentiated-immature areas of proliferation. Wide intercellular spaces between irregular cytoplasms with protrusions and microvilli, a high incidence of indentations of nuclear membranes, a large amount of nuclear bodies, shape, size and structure anomalies of mitochondria, a great number of desmosomes and of tonofilaments and tonofibril bundles and their relations with desmosomes and with the finger-like cytoplasmic expansions were noticed. A few secretory granules were also present in these poorly differentiated-immature areas of epidermoid carcinomas of the lung.

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Lipid lamellated vacuoles have been found in epithelial cells lining bile ducts in a case of Niemann-Pick's disease. The lipidic vacuoles were few and small within these cells and were placed in the cell apical area.

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Based on previous data, this research deals with the study of cellular ultrastructure of renal tissue (cortical and medullary) in conditions of preservation through a continuous hypothermic pulsatile perfusion, using a solution that substitutes plasma as the perfusate. This experiment was done on isolated dog kidneys perfused with a specialized perfusion machine. The results clearly show that with this method of renal preservation, no major lesions or irreversible modifications of the nephrons occur within 12 hours, offering the organ posttransplanting compatibility.

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A total of 60 cases are presented, of patients with tumours of the soft parts of the limbs, from a total of 14,000 surgical interventions. Of the total 18 were malignant tumours, while the remaining 42 cases had benign tumours. Tumours of the soft parts of the limbs include a large variety of histologic forms, and this raises particular problems of diagnosis and treatment. In the case of benign tumours the treatment is better codified, and consists in the removal of the tumour by simple enucleation. Recidives are possible because of the infra-clinical peritumoral invasion. In the case of malignant tumors the treatment is more differentiated, depending on the histologic type, the degree of malignancy, the stage of evolution, and on evolutive characteristics. Surgery remains an essential part of the treatment, and either limited or radical surgical solutions (amputation) are used. Frequently radiation and chemical therapy are associated, with good results. Six clinical observations are presented: rhabdomyosarcoma of the recidivating type, multi-recidivating fibrosarcoma, fibromyxosarcoma, varicose ulcers with malignant evolution, and two cases of liposarcoma. The cooperation is stressed, which should exist between the surgeon, the pathologist, radiologist and oncologist, for the diagnosis and treatment of these affections.

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The phyllodes tumour is a bi-tissular mammary tumour. It is essentially benign but potentially sarcomatous, presenting multiple clinical and histologic-aspects, and raises difficult problems of diagnosis and therapeutic attitude. Four histological types are described, from the adenofibromatous type to the sarcomatous one. The notion of local malignancy is discussed, related to the marked recidivating character of the tumour. The morphologic substrate of the recidivating character is the result of the absence of a true capsule of the tumour. The treatment is differentiated according to the clinic, histologic, and recidivating aspects, and consists in either sectorectomy or breast amputation. Five cases are presented, of phyllodes tumour, each of them with particular characteristics of evolution, and imposing differentiated therapeutic attitudes.

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Six bronchopulmonary carcinomas of various histological types (macrocellular, epidermoid) were electronmicroscopically studied on bronchial biopsy samples. The scarcity of intercellular junctions was observed in all of them, especially in carcinoma types or zones (i.e. of epidermoid carcinoma) less differentiated. Close and gap junctions, zonulae adherentes and maculae adherentes dominated the structure of poorly differentiated carcinomas, while the differentiated types also presented frequent desmosomes. Also the reduction of intercellular junctions frequency was accompanied by their ultrastructural aberrations. The ultrastructural changes observed were correlated to the capacity for invasion of investigated carcinomas without reducing this basic property of cancer cells to the former.

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The freeze-fracture appearance of fenestrations of sinusoidal endothelial cells has been reassessed in perfusion-fixed rat liver. Fenestrations, limited to the attenuated portions of the endothelial cell cytoplasm are usually round or oval in shape, with diameters ranging from 40-600 nm. Within a given fenestrated region, they are disposed in clusters forming sieve plates. In addition, the presence of wide, irregularly shape openings suggest that adjacent fenestrations may coalesce and result in the larger openings. Our data thus confirm the existence of both small and large fenestrae in the endothelial wall, in contradistinction to previous studies showing only regular, medium sized (100 nm) openings.

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