垂体性闭经是怎么一回事?What is pituitary amenorrhea?

陈凤林教授指出：垂体性闭经是由于垂体病变致使Gn分泌降低而引起的闭经。常见的垂体性闭经原因有以下几方面：

Professor Chen Fenglin pointed out that pituitary amenorrhea is caused by the decrease of Gn secretion caused by pituitary lesions. The common causes of pituitary amenorrhea are as follows:

1.垂体肿瘤

位于蝶鞍内的腺垂体中各种腺细胞均可发生肿瘤，最常见的是分泌PRL的腺瘤，闭经程度与PRL对下丘脑GnRH分泌的抑制程度有关。若发生在青春期前，则可引起原发性闭经。根据肿瘤的性质不同，临床上可有溢乳、巨人症、皮质醇增多症等肿瘤所特有的症状，还可出现头痛、视力障碍、视野缺损等神经受压的症状。

1. Pituitary neoplasms

Tumors can occur in all kinds of adenohypophysis cells located in sella turcica. The most common adenoma secreting PRL is adenoma. The degree of amenorrhea is related to the inhibition of PRL on GnRH secretion in hypothalamus. If it occurs before puberty, it can cause primary amenorrhea. According to the nature of the tumors, there may be clinical symptoms of galactorrhea, gigantism, hypercortisolism and other specific tumors, as well as nerve compression symptoms such as headache, visual impairment, visual field defect.

2.空蝶鞍综合征

由于蝶鞍隔先天性发育不全，或肿瘤及手术破坏蝶鞍隔，使充满脑脊液的蛛网膜下腔向垂体窝(蝶鞍)延伸。压迫腺垂体，使下丘脑分泌的GnRH和多巴胺经垂体门脉循环向垂体的转运受阻，从而导致闭经，可伴PRL水平升高和溢乳。

2. Empty sella syndrome

Because of congenital hypoplasia of sellar septum, or the destruction of sellar septum by tumors and surgery, the subarachnoid space filled with cerebrospinal fluid extends to the pituitary fossa (sella). Compression of the pituitary gland hinders the transport of GnRH and dopamine secreted by the hypothalamus through the pituitary portal circulation to the pituitary gland, leading to amenorrhea, which may be accompanied by elevated PRL level and galactorrhea.

3.先天性垂体病变

先天性垂体病变包括单一Gn分泌功能低下的疾病和垂体生长激素缺乏症;前者可能是LH或FSH的α、β亚单位分子结构异常或其受体异常所致;后者则是由于脑垂体前叶生长激素分泌不足所致。

|3. Congenital pituitary diseases

Congenital pituitary diseases include hypofunction of single Gn secretion and hypophyseal growth hormone deficiency; the former may be caused by abnormal molecular structure of alpha and beta subunits of LH or FSH or abnormal receptors; the latter is caused by insufficient secretion of growth hormone in the anterior pituitary.

4.Sheehan综合征

Sheehan(席汉)综合征是由于产后出血和休克导致的腺垂体急性梗死和坏死，可引起腺垂体功能低下，从而出现低血压、畏寒、嗜睡、食欲减退、贫血、消瘦、产后无泌乳、脱发及低Gn性闭经。

4. Sheehan syndrome

Sheehan syndrome is caused by acute infarction and necrosis of the pituitary gland caused by postpartum hemorrhage and shock. It can cause hypophysis, chills, sleepiness, loss of appetite, anemia, emaciation, postpartum lactation, alopecia and low Gn amenorrhea.