|
Pituitary adenomas are tumors that occur in the pituitary gland. Pituitary adenomas are generally divided into three categories dependent upon their biological functioning: benign adenoma, invasive adenoma, and carcinomas, with carcinomas accounting for 0.1% to 0.2%, approximately 35% being invasive adenomas and most being benign adenomas. Pituitary adenomas represent from 10% to 25% of all intracranial neoplasms 〔()〕 and the estimated prevalence rate in the general population is approximately 17%.〔 Non-invasive and non-secreting pituitary adenomas are considered to be benign in the literal as well as the clinical sense; however a recent meta-analysis (Fernández-Balsells, ''et al.'' 2011) of available research has shown there are to date scant studies - of poor quality - to either support or refute this assumption. Adenomas which exceed in size are defined as ''macroadenomas'', with those smaller than 10 mm referred to as ''microadenomas''. Most pituitary adenomas are microadenomas, and have an estimated prevalence of 16.7% (14.4% in autopsy studies and 22.5% in radiologic studies). A majority of pituitary microadenomas often remain undiagnosed and those that are diagnosed are often found as an ''incidental finding'', and are referred to as ''incidentalomas''. Pituitary macroadenomas are the most common cause of hypopituitarism, and in the majority of cases they are non-secreting adenomas.〔Hyperthyroidism unmasked several years after the medical and radiosurgical treatment of an invasive macroprolactinoma inducing hypopituitarism: a case report. L Foppiani, A Ruelle, P Cavazzani, P del Monte - Cases journal, 2009〕 The Pituitary gland is in close proximity to the brain, invasive adenomas may invade the dura mater, cranial bone, or sphenoid bone. While Pituitary adenomas are extremely common, affecting approximately one in 6 of the general population, clinically active pituitary adenomas requiring surgical treatment are more rare, affecting approximately one in 1000 of the general population. ==Signs and symptoms== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pituitary adenoma」の詳細全文を読む スポンサード リンク
|