The syndrome of testicular feminization

Timing of gonadectomy in adult women with complete androgen insensitivity syndrome (CAIS): patient preferences and clinical evidence

OBJECTIVE

Adult women with complete androgen insensitivity syndrome (CAIS) are increasingly likely to defer or decline gonadectomy despite counselling about malignancy risk. The objectives of this study were to review the evidence on the risk of gonadal malignancy in adult women with CAIS and to explore women's reasons for deferring gonadectomy.

STUDY DESIGN

A case series and literature review.

PATIENTS

Sixteen women with CAIS over the age of 18 years who have elected to defer gonadectomy.

RESULTS

Sixty-two relevant papers were identified. Of these, 14 confirmed that tumours had been reported in 98 adults. Taking into account the limitations of combining historic case series, this review estimates a risk of gonadal malignancy of 14% (range 0% and 22%) in adults with CAIS. The most common reasons women offered for deferring gonadectomy included inconvenience of surgery, concern about surgical risk and reluctance to take hormone replacement therapy.

CONCLUSIONS

Perceived benefits for retaining gonads in women with CAIS are prompting more women to keep their gonads in situ. An accurate estimate for adult malignancy risk is unavailable, and the risks currently quoted may be falsely reassuring.

Endocrine and morphological perspectives in testicular descent

Before sexual differentiation occurs at seven weeks, the urological ridges develop in the embryo. These contain the primitive gonads, the mesonephros (embryonic kidneys) and the paired Wolffian (mesonephric) ducts, along with the Müllerian (paramesonephric) ducts. The fundamental mechanism of fetal sexual development was elucidated by Alfred Jost and is determined by the development of the gonad: where testes form in response to the testis-determining gene, and the male testicular hormones cause development of the male phenotype. If ovaries develop or the gonads are absent, female secondary sex characteristics are produced. Recently, the cloning of the putative human testis-determining gene on the Y-chromosome was reported. Assuming this is the true controller of testicular development, an understanding of the initiation of sexual differentiation at the genetic level should emerge in the near future. Of great importance will be the isolation of the testis-determining gene product and identification of other genes that it regulates.

Huge seminoma developed in a patient with testicular feminization

We report a 36-year-old patient who presented with primary amenorrhea and was found to have a giant abdominal tumor. There was a family history of primary amenorrhea in her two aunts. Physical and hormonal examinations as well as chromosomal analysis led to a diagnosis of testicular feminization. The patient underwent tumorectomy along with pelvic and para-aortic lymphadectomy. The pathological diagnosis was bilateral seminoma of the testis with metastasis to para-aortic lymph nodes. Nowadays, cases of undiagnosed seminoma developing into a huge abdominal mass in patients with testicular feminization are rarely encountered, since surgical castration is generally recommended as early as possible after puberty. In testicular feminization, the risk of malignant transformation of the dysgenetic male gonads increases substantially after puberty. Early and correct diagnosis together with careful follow-up are critically important in managing testicular feminization, a rare congenital disorder.

Laparoscopic gonadectomy in two patients with gonadal dysgenesis

Individuals with androgen insensitivity syndrome have a high risk (20-30%) of developing malignancy in their gonads. Accordingly, bilateral gonadectomy is recommended. In a 17-year-old woman with Swyer syndrome gonads were located as streaks above the pelvic brim. In a 13-year-old with Morris syndrome they were located within the inguinal canals. Bilateral laparoscopic gonadectomy was performed under general anesthesia in both patients without complications. We suggest that in phenotypic females with 46,XY karyotype, the procedure may be performed safely, even with gonads located in inguinal canals.

The surgical management of incomplete testicular feminization syndrome in three sisters

Three sisters with incomplete testicular feminization syndrome are presented. Most of the patients with this syndrome are females and surgery is an important part of their multidisciplinary treatment. Two of the sisters had gonadectomies, herniorrhaphies, vaginoplasty with neurovascular pudendal thigh flaps, reduction clitoroplasty and labia minora reconstruction. The third sister had sufficient vaginal depth and had release of an introitus skin web, clitoroplasty and labia minora reconstruction. All patients had a good result. The reconstructed vaginas are stable and sensate.

Male pseudohermaphroditism in XY children with female phenotype

Twenty-two children with female external genitalia, testes, and 46,XY karyotype, most presenting with inguinal lumps or hernias, underwent bilateral gonadal excision (21 patients) or biopsy. On clinical and biochemical grounds, 13 were classed as androgen resistance (AR), 6 as testosterone biosynthetic defect, 2 as XY gonadal dysgenesis, and 1 as 5 alpha-reductase deficiency. The main pathological difference between the groups was that in AR the gonocytes were present in normal numbers, whereas in testosterone biosynthetic defect, gonocytes, though present in infancy, were rare or absent by 12 years. In all groups, Leydig cells, normally not recognizable between 1 year and puberty, were often present and could not always be attributed to a gonadotropin stimulation test. In four cases the tubules were more heterogeneous than those seen in control testes, but tubular atrophy and increased stroma were indistinguishable from those in age-matched cryptorchid controls. Small Sertoli cell nodules were found in three children, but no carcinoma in situ was identified. The epididymis, said to be absent in adult cases of AR, was consistently present but often cystic or atrophic. Oviduct-like structures were found in three cases of AR, and smooth muscle resembling round ligament in four. Because of the difficulty in distinguishing the types of male pseudohermaphroditism microscopically, we recommend that XY female children should undergo thorough endocrinologic investigation before orchidectomy.

Seminoma in pubertal patient with androgen insensitivity syndrome

The case of a 14-year-old girl with complete androgen insensitivity syndrome and metastatic seminoma is reported. She was treated by bilateral adnexectomy, removal of paraaortic lymph nodes, postoperative radiation, and estrogen replacement therapy. She represents the fourth case of gonadal malignancy to be reported in a teenage patient with androgen insensitivity syndrome.

Failure of the müllerian regression factor in two patients with complete androgen insensitivity syndrome

The present paper describes the histological and endocrinologic features of 2 subjects with 46,XY karyotype affected by complete androgen insensitivity syndrome (AIS) with müllerian structures. Both patients had fallopian tubes, but only one had also uterus and presented a seminoma. Serum levels of luteinizing hormone, testosterone and estradiol were high or in the upper part of normal limits, whereas levels of follicle-stimulating hormone were normal. The association between AIS and the presence of müllerian structures observed in these 2 patients might be explained by an impaired synthesis of müllerian regression factor or by a failure in its mechanism of action.

The syndromes of androgen resistance revisited

A revisit to the existing complexities of the androgen resistance syndromes within the frame of our current knowledge was undertaken. Recent contributions of these and other laboratories are presented according to the topographic intracellular location of the underlying abnormalities causing these inherited disorders. Thus, the clinical spectrum, inherited pattern and biochemical features of defective androgen action at the pre-receptor, receptor, and post-receptor levels are examined. In addition, the effects of androgens on the development of gender role is discussed, with particular focus on patients with pre-receptor defects. It was concluded that a better understanding of the nature of the altered events in these syndromes has been achieved over recent years, although several important issues still remain unsolved.

Testicular feminization: a model for testicular descent in mice and men

The position of the testis was determined in patients and mice with the testicular feminization (TFM) syndrome, to answer the question, do androgens cause testicular descent? In 16 children with complete or partial TFM syndrome with androgen insensitivity, plus two children with a deficiency of androgen secretion, the testes were at or beyond the internal inguinal ring in 35 out of 36 instances. In male mice with TFM, the testes had descended normally to the internal ring by the time of birth but further descent was absent. These observations suggest testicular descent is a two-stage process comprising transabdominal and transinguinal phases. The first phase is not controlled by androgen, and hence is normal in TFM; by contrast the second phase is androgen-dependent, and absent in TFM. It is speculated that the first phase may be regulated by Müllerian Inhibiting Substance, although this is unproven. Because testicular descent in TFM can be separated into two stages, the TFM mouse should prove a useful model for studying the hormonal control of descent of the testis.

Androgen receptors

Testosterone and its active metabolite dihydrotestosterone exert their influence on target cells through a specific intracellular protein receptor. Structural abnormalities of this receptor lead to a diminished androgen action within the cell and result in the syndrome of androgen insensitivity. Androgen insensitivity is classified on the basis of whether the insensitivity is complete or partial and whether the androgen receptor is normally present (AR(+)), absent (AR(-)) or diminished (AR(+/-)). All patients with androgen insensitivity have normal or high plasma levels of testosterone and elevated serum LH. Patients with complete androgen insensitivity are phenotypically female. The clinical presentation of partial androgen insensitivity is variable, ranging from a minimal amount of virilization to a completely masculine appearance. All patients described with a syndrome of androgen insensitivity are infertile. The influence of androgen receptor function in the pathogenesis of benign prostatic hypertrophy is being investigated. Androgen receptor content is also being studied as a possible marker of responsiveness to hormonal therapy in prostatic carcinoma.

Mechanical genital maldevelopment presenting as pseudovaginal perineoscrotal hypospadias

Pseudovaginal perineoscrotal hypospadias is the descriptive terminology of a phenotypic genital abnormality that may develop from multiple etiologic factors, such as defective virilization-masculinization owing to deficient androgenic synthesis, defective androgenic action or mechanical embryologic failure. The case presented herein typifies a mechanical abnormality that results in perineal hypospadias with the appearance of a vaginal introitus but with rectal mucosa incorporated in the urethral opening.

Testicular feminization syndrome: current clinical considerations

The testicular feminization syndrome (TFS) in its complete form results in total feminization due to a nuclear inaction of androgens, and the female role should be supported with postpubertal orchiectomy to avoid the risk of malignancy. Incomplete forms of the syndrome (ITFS) include Type I n which some degree of masculinization may be observed, prompting earlier gonadectomy, and Type II or pseudovaginal perineoscrotal hypospadias (PPSH) which is always characterized by pubertal masculinization, necessitating management and support of these patients as males. Other intersex abnormalities which must be differentiated include true hermaphroditism, the Swyer syndrome, males with 17-ketosteroid reductase deficiency, and Reifenstein's syndrome.

Fetal phallic growth and penile standards for newborn male infants

No appreciable difference in size of the fetal clitoris versus the fetal penis was noted until 14 weeks' gestation, which is after the period of masculine differentiation of the external genitals. However, significant differences in the rate of penile and clitoral growth were evident in second trimester fetuses. The majority of the prenatal growth of the penis occurs after 14 weeks gestation at an almost linear rate. The penile stretched length of the full-term infant was 3.5 cm plus or minus 0.7 cm and the diameter was 1.1 cm plus or minus 0.2 cm.