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The term aneurysm is used to indicate a permanent and irreversible localized vascular dilatation that involves all three layers of the blood vessel wall. It may develop in any part of the circulatory system, including veins, and its history, presentation, and management differ depending on the location. A venous aneurysm is defined as a solitary area of fusiform or saccular dilatation occurring in the course of a major vein or connected by a single channel to a major venous structure. The lower extremities are the most frequently affected, with the popliteal vein being the most common site. Although different theories have been advanced, the etiology of the disease remains uncertain. Mechanical stress and/or degenerative changes within the vein wall are believed to represent the most likely causes of venous aneurysm. To date, there are only a few publications dealing with the histological appearance of popliteal vein aneurysm, and no studies that specifically describe its ultrastructural details have been published to our knowledge. In an attempt to fill this gap and to provide better insights into the pathophysiological mechanisms possibly involved in aneurysmal venous disease, we describe the fine structure of popliteal vein wall and valve in health and disease using both scanning and transmission electron microscopy.

Ultrastructural data about large cell variant ovarian small cell carcinoma (LCV-SCC) are scarce and contradictory and the role of transmission electronmicroscopy (TEM) is not clear in the assessment of such tumors. The authors present a case of LCV-SCC without hypercalcemia in a 30-year-old woman. The diagnosis was confirmed by histopathological and immunohistochemical studies. Cytopathological examination of peritoneal washing showed a population of large neoplastic cells. TEM demonstrated that the neoplasia comprised two types of cells: one type showed many coarse secretory granules without dense core, and the other type was without granules and showed dilated endoplasmic reticulum and sometimes indented nuclei. The present case indicates that different underlying ultrastructural patterns, not yet well known, exist in connection with the pathological and clinical behaviour of LCV-SCC. TEM might play a role in the identification of subtypes of LCV-SCC with different prognostic and therapeutic impact.

Chordoid meningioma (CM) is a meningioma containing regions that are histologically similar to chordoma, with trabeculae of eosinophilic, vacuolated cells in a myxoid background and corresponds to ...

Osteonecrosis of the jaw is a severe bone disorder traditionally associated with periodontal disease, local malignancy, chemotherapy, glucocorticoid therapy, or trauma. Recently a growing number of publications reported the occurrence of osteonecrosis of the jaw in patients undergoing treatment with bisphosphonates. The mechanism by which bisphosphonates might contribute to the development of osteonecrosis of the jaw is far from being fully elucidated. Suppression of bone turnover, infection, tissue hypoxia and cellular toxicity were proposed as possible mechanisms by which bisphosphonates may exert adverse effects on bone metabolism. Here, we studied 25 consecutive patients treated with bisphosphonates for osteoporosis or tumoral pathologies. We provide good evidence of hyperactive osteoclastic bone resorption and suggest a direct cytotoxic effect of bisphosphonates on bone tissue through induction of osteocyte cell death. We also demonstrate that bisphosphonates only have limited adverse effects on bone vascular network.