They remain fully contained within a prostate acinus (the berry-shaped termination of a gland, where the secretion is produced) or duct. The latter can be demonstrated with special staining techniques (immunohistochemistry for cytokeratins) to identify the basal cells forming the supporting layer of the acinus. In prostate cancer, the abnormal cells spread beyond the boundaries of the acinus and form clusters without basal cells. In HGPIN, the basal cell layer is disrupted but present. PIN is primarily found in the peripheral zone of the prostate (75-80%), rarely in the transition zone (10-15%) and very rarely in the central zone (5%), a distribution that parallels the zonal distribution for prostate carcinoma.Because it is thought to be a premalignant state, PIN is often considered the prostate equivalent of what is called carcinoma in situ (localized cancer) in other organs. However, PIN differs from carcinoma in situ in that it may remain unchanged or even spontaneously regress.Several architectural variants of PIN have been described, and many cases have multiple patterns. The main ones are tufting, micropapillary, cribriform, and flat. Although these different appearances may cause confusion with other conditions, they have not been found to be of clinical importance. Rarer types are signet-ring-cell, small-cell-neuroendocrine, mucinous, foamy, inverted, and with squamous differentiation.
Hydrocortisone sodium succinate is a synthetic glucocorticoid corticosteroid and a corticosteroid ester. == References ==