In endocrine clinical work, amenorrhea is common in patients. Amenorrhea is closely related to endocrine disorders. According to the traditional classification of amenorrhea is divided into primary and secondary amenorrhea. Primary amenorrhea is said to occur in about 5% of women who have reached the age of 18 and still do not have menstrual flow. At present, the internationally accepted definition of primary amenorrhea is: (1) no menstruation at the age of 14 and no development of secondary sex characteristics; (2) no menstruation at the age of 16, regardless of whether the secondary sex characteristics are normally developed or not. The causes and parts of amenorrhea are classified as follows: 1. Hypothalamic pituitary abnormalities Hypogonadotropic hypogonadism is caused by insufficient secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus or insufficient secretion of gonadotropin from the pituitary gland, mainly manifesting as primary amenorrhea, absence of secondary sexual characteristics, female The main manifestations are primary amenorrhea, absence of secondary sexual characteristics, normal differentiation of internal genitalia but smaller uterus, some patients may have hyposmia or loss of smell.
2. Anterior pituitary amenorrhea 2.1 Pituitary adenoma ① Prolactin adenoma: It is a common functional adenoma of the anterior pituitary gland, benign, secreting prolactin (PRL), with a slow growth rate. Clinical manifestations include amenorrhea, overflowing breast, infertility, tumor compression symptoms, hypoestrogenic symptoms and hyperprolactinemia.
Gonadotropin adenoma: It is a non-functional pituitary adenoma that secretes follicle stimulating hormone (FSH) and luteinizing hormone (LH). The expression of activin, inhibin and follicle inhibitor can be used as tumor markers. Microadenomas are mostly asymptomatic, while giant adenomas may cause visual field defects, headache and hypopituitarism.
(3) Thyrotropin adenoma: It is a basophilic or suspicious cell tumor and is rarely seen clinically. Thyrotropin adenoma secretes too much thyrotropin hormone (TSH) and causes pituitary hyperthyroidism and amenorrhea. CT and MRI should be performed to confirm whether there is a pituitary tumor and the size of the tumor, and once diagnosed, surgery should be performed.
④Growth hormone adenoma: It is an anterior pituitary eosinophilic tumor. The tumor cells secrete too much growth hormone, which may cause gigantism with gonadal hypoplasia and primary amenorrhea.
2.2 Primary pituitary insufficiency ① Empty saddle syndrome: first described by Bosch in 1951, congenital saddle septal defect, incomplete or underdeveloped saddle, manifested by flattened pituitary gland and empty pituitary fossa. ACTH) and growth hormone (GH) deficiency and increased PRL.
Mutations in genes that control pituitary development: The development of anterior pituitary hormone-secreting cells requires a series of genes that control pituitary development. PIT I1 and PROP I1 mutations are associated with pituitary hormone deficiency syndrome, resulting in deficiencies of GH, PRL, TSH, FSH and LH.
2.3 Single pituitary gonadotropin deficiency ①Single growth hormone deficiency: It may be a pituitary growth hormone deficiency due to mutations in GH gene or gonadotropin-releasing hormone (GnRH) receptor gene. Patients do not develop secondary sexual characteristics after puberty, and develop primary amenorrhea and backward bone age.
(2) Single gonadotropin deficiency: It may be due to LH, FSH synthesis disorder or abnormal function, or due to the pituitary gland’s own GnRH receptor gene mutation, resulting in hypothalamic secretion of hormone in the pituitary signal transduction disorder, anterior pituitary secretion of gonadotropin reduced, hypogonadism, no secondary sex characteristics development and sexual infantile, primary amenorrhea.
3, ovarian amenorrhea 3.1 congenital gonadal dysgenesis (Turner syndrome): caused by the deletion or mutation of an x chromosome, the karyotype is mainly 45, XO. In addition, a variety of chimeric types can be seen, such as 45, X0/46, XX; 46, XX/47, XXX; 45, X0/47, XXX; 46, XX/47, XX+21, etc.. The manifestations are gonadal dysplasia, absence of secondary sexual characteristics, and uterine dysplasia; often combined with abnormalities of the urinary and cardiovascular systems.
3.2 Ovarian resistance syndrome: Ovarian insensitivity syndrome with karyotype 46, XX. It may be due to lack of gonadotropin (Gn) receptor or Gn receptor mutation in the ovary, or lack of effective ovarian response to endogenous or exogenous Gn due to abnormal ovarian local regulatory factors. Patients present with primary amenorrhea, poorly developed or non-developed secondary sexual characteristics, and normal growth and development.