Browsing by Subject "Pituitary adenomas"

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    Light microscopical morphometry of prolactin secreting adenomas under treatment with dopamine agonists
    (Murcia : F. Hernández, 1987) Hamester, U.; Saeger, W.; Ludecke, D.K.
    In order to study the light microscopical alterations of pituitary tumours under dopamine agonist treatment, three groups of a total of 18 large or small cell chromophobe adenomas were analysed by light microscopical, immunohistological and morphometrical methods. They were all removed by transsphenoidal surgery. 6 of them were treated preoperatively with dopamine agonists, bromocriptine andlor lisuride, for various periods of time. 8 adenomas remained preoperatively untreated. 4 additional untreated tumors were small cell inactive adenomas for comparison. One case was excluded from the final evaluation of the data because it appeared to be a typical non-responder, clinically as well as histologically. Immunohistological positivity for prolactin was to be found in all cases in various degrees. Clinically active adenomas contained many prolactin positive cells, whereas in inactive adenomas only scattered cells were prolactin positive. The morphometric analysis revealed a reduction of the cytoplasmic area in a statistically significant degree in the group of adenomas under treatment, which explains adequately the shrinkage of the entire adenoma and the reduction of prolactin plasma levels. The morphometric data of treated adenomas resembled those of untreated inactive adenomas.
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    Previously unreported "hemidesmosomal junctions", between folliculo-stellate cells and pituitary adenoma cells
    (Murcia : F. Hernández, 1988) Osamu Tachibana; Tetsumori Yamashima
    Thirty-eight non-functioning pituitary adenomas were ultrastructurally investigated with particular attention to the Folliculo-Stellate (FS) cells. A large number of FS cells were found in four cases, one of which disclosed a new type of intercellular junction between FS cells and surrounding adenoma cells. These junctions were characterized by 1) the presence of plasmalemmal attachment plaques only in FS cells, 2) the cytoplasmic filaments assembling in parallel to the attachment plaques, 3) the parallel plasma membranes being separated by the intercellular amorphous material and 4) the intercellular space of approximately 25nm width. They were similar to hemidesmosomes, but were quite different from hemidesmosome-like intercellular specializations which have been described in the normal meninges and human meningiomas. Accordingly, we designated these new junctions as nhemidesmosomal int~ctionsu which appeared to be one of the ultrastructural features characterizing FS cells.