Anorchia

　　First, etiology

　　The cause of congenital anorchia has not been confirmed so far and may be related to the following two aspects.

　　First, during the process of embryonic development, sexual gland development is impaired due to interference from some factors. Lobacarro et al. believe that an abnormal SRY gene on the Y chromosome sex-determining region can lead to anorchia.

　　Second, testicular torsion, spermatic cord thrombosis during pregnancy or shortly before or after birth, leading to obstruction of testicular blood supply and testicular atrophy, may be the most common cause.

　　Second, pathogenesis

　　At 8 weeks of gestation, the testicular tissue begins to develop and secrete anti-Mullerian hormone (anti-Mullerian hormone, AMH), and then secretes testosterone. If the testicular tissue is lost before secreting testosterone, the Mullerian duct has regressed, but the androgen-dependent differentiation of Wolffian ducts, urogenital sinus, and male external genitalia has not yet begun. If the testicular tissue originally existed and secreted testosterone for a period of time, the androgen-dependent target organs of the urogenital tract will develop somewhat towards the male direction.

　　Congenital bilateral anorchid patients with AMH secretion but no testosterone secretion present as male pseudohermaphroditism, with female-type external genitalia. Patients not only lack Mullerian duct-derived reproductive organs (uterus, fallopian tubes, and upper vagina), but also lack Wolffian duct-derived reproductive organs (epididymis, vas deferens, and seminal vesicle). If the testicular tissue secretes testosterone during embryonic development, the external genitalia will be male, and the Wolffian duct-derived reproductive organs can develop. A small penis to some extent reflects the stagnation of embryonic development of testosteron-dependent organ development. If not treated, the patients with congenital bilateral anorchidism will show a typical eunuchoid appearance due to the stagnation of adolescent development. Since a single testicle can meet the physiological functional needs, patients with unilateral congenital anorchidism will not show abnormal gender development during puberty, but there may be residual Mullerian ducts on one side, which mainly depends on the time of loss of testicular tissue.

　　For patients with congenital bilateral absence of testicles, it is not only impossible to find testicular tissue from a histological standpoint, but also to find testicular function from an endocrine function perspective. The serum follicle-stimulating hormone (FSH) and plasma luteotropin (LH) levels in children are already elevated, and by the time of puberty, they have reached castration levels, while in contrast, the testosterone level is very low.

　　This disease is prone to infertility. It can lead to an absence of libido, azoospermia, impotence, and other conditions that cause infertility. At the same time, the main function of the testicles is to secrete androgens. Therefore, patients with eunuchoidism may experience a decrease in androgen secretion due to the absence of testicles, which limits the development of secondary sexual characteristics and reproductive organs. Due to the decrease in androgens, estrogen becomes relatively hyperactive, which can lead to feminization manifestations such as a feminine voice and breast development.

　　For individuals with unilateral absence of testicles, their penis and scrotum develop normally. Due to compensatory hyperplasia of the healthy side testicle, the testosterone level in the blood is normal, and the secondary sexual characteristics during puberty are normal. For individuals with bilateral absence of testicles, the patients have no developmental ability and present as eunuchoid development, characterized by abundant subcutaneous fat, delicate skin, a high-pitched voice, and physical examination findings of underdeveloped scrotum, empty scrotum without testicles, small penis, and no hair growth.

　　This disease belongs to sex chromosome disease, and the etiology of chromosomal malformation is unclear, which may be related to environmental factors, genetic factors, dietary factors, and emotional and nutritional factors during pregnancy. Therefore, this disease cannot be prevented directly. Regular checks should be done during pregnancy. If the child shows a tendency of abnormal development, chromosomal screening should be done in a timely manner, and artificial abortion should be performed as soon as possible to avoid the birth of children with the disease.

　　1. The sex hormone test has certain guiding significance in determining the presence or absence of testicles and deciding whether to perform exploratory surgery. If the bilateral testicles cannot be felt, and if LH and FSH levels are elevated, intramuscular injection of chorionic gonadotropin (hormone chorionic gonadotropin, HCG) 1000-1500U, once every other day, for a total of 3 times, and a re-examination of serum testosterone does not increase, it can be diagnosed as congenital absence of testicles, and there is no need for exploratory surgery. If the serum testosterone level increases after injection of HCG, or although the serum testosterone level does not change, but LH and FSH do not increase, it is necessary to perform exploratory surgery because at least one testicle exists.

　　2. Invasive examinations such as testicular arteriography or venography have low accuracy and certain complications and are now rarely used. Non-invasive examinations such as ultrasound, CT, MRI, etc., do not have specificity and can only be used as a reference. Currently, laparoscopic technology can safely and accurately diagnose intra-abdominal cryptorchidism and anorchia, thus avoiding blind exploration.

　　In addition to conventional treatment, attention should also be paid to related matters in diet for patients with anorchia. In daily life, fresh vegetables and fruits should be eaten more to increase the intake of vitamin C and other components, in order to improve the body's anti-inflammatory ability.

　　1. In the case of unilateral anorchia, since the contralateral testicle functions normally, and there are no other concurrent malformations, treatment is not required. From the psychological perspective of the patient, artificial testicles can be implanted in the scrotum as prosthetics, which are satisfactory in terms of appearance and sensation, except for the lack of function.

　　2. In the case of bilateral anorchia in infants and young children, sex reassignment surgery can be considered, with clitoral molding surgery first, followed by vaginal molding surgery during puberty. Early determination of gender can alleviate the parents' anxiety if raised as a girl. If sex reassignment surgery is refused, early application of androgen therapy, such as intramuscular testosterone injection, should be considered to promote the development of the penis and scrotum.

　　3. In the case of bilateral anorchia during puberty, hormone replacement therapy with androgens can be considered, and intramuscular testosterone injection can be used to promote masculinization. Infertility due to bilateral anorchia is uncurable. To meet the psychological needs of patients, artificial testicles can be implanted in the scrotum as prosthetics. In addition, allogeneic testicle transplantation can also be chosen. Like other organ transplants, allogeneic testicle transplantation requires preoperative tissue matching to exclude donor testicular, epididymal, and vas deferens diseases.