The preparation was originally developed in 1986 by a compounding pharmacy called Madison Pharmacy Associates in Madison, Wisconsin in the United States. Vaginal, rectal, and uterine
Vaginal progesterone suppositories were first studied in women by Robert Greenblatt in 1954. Shortly thereafter, vaginal progesterone suppositories were introduced for medical use under the brand name Colprosterone in 1955. Rectal progesterone suppositories were first studied in men and women by Christian Hamburger in 1965. Vaginal and rectal progesterone suppositories were introduced for use under the brand name Cyclogest by 1976. Vaginal micronized progesterone gels and capsules were introduced for medical use under brand names such as Utrogestan and Crinone in the early 1990s. Progesterone was approved in the United States as a vaginal gel in 1997 and as a vaginal insert in 2007. A progesterone contraceptive vaginal ring known as Progering was first studied in women in 1985 and continued to be researched through the 1990s. It was approved for use as a contraceptive in lactating mothers in Latin America by 2004. A second progesterone vaginal ring known as Fertiring was developed as a progesterone supplement for use during assisted reproduction and was approved in Latin America by 2007.Development of a progesterone-containing intrauterine device (IUD) for contraception began in the 1960s. Incorporation of progesterone into IUDs was initially studied to help reduce the risk of IUD expulsion. However, while addition of progesterone to IUDs showed no benefit on expulsion rates, it was unexpectedly found to induce endometrial atrophy.
Pleomorphism is a term used in histology and cytopathology to describe variability in the size, shape and staining of cells and/or their nuclei. Several key determinants of cell and nuclear size, like ploidy and the regulation of cellular metabolism, are commonly disrupted in tumors. Therefore,  cellular and nuclear pleomorphism is one of the earliest hallmarks of cancer progression and a feature characteristic of malignant neoplasms and dysplasia. Certain benign cell types may also exhibit pleomorphism, e.g. neuroendocrine cells, Arias-Stella reaction. A rare type of rhabdomyosarcoma that is found in adults is known as pleomorphic rhabdomyosarcoma.Despite the prevalence of pleomorphism in human pathology, its role in disease progression is unclear. In epithelial tissue, pleomorphism in cellular size can induce packing defects and disperse aberrant cells. But the consequence of atypical cell and nuclear morphology in other tissues is unknown. See also
Anaplasia
Cell growth
Cytopathology
Giant cell carcinoma of the lung
Nuclear atypia


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