The fine structure of the gonads in the complete form of testicular feminization syndrome

Perspectives in Pediatric Pathology, Chapter 6. Male Undermasculinization

Normal male development requires three conditions: (1) adequate differentiation of the fetal testis; (2) synthesis and secretion of testicular hormones; and (3) effective action of these hormones on target organs. This requires the combined action of the inhibitory anti-müllerian hormone (AMH, secreted by Sertoli cells) to block the development of the uterus and fallopian tubes from the müllerian duct, together with the trophic stimulus of testosterone (a Leydig cell product), which leads to virilization of the wolffian ducts. Additionally, the development of external genitalia depends on the conversion of testosterone to dihydrotestosterone by the enzyme 5-α-reductase. Failure of any of these mechanisms leads to deficient virilization or the so-called "male pseudohermaphroditism" syndromes.

The functional significance of FSH in spermatogenesis and the control of its secretion in male primates

The aim of this review is to provide an integrative analysis of the role of FSH in the control of testicular function in higher primates, including man. Attention is focused on the action of FSH during neonatal development, puberty, and adulthood. Whether FSH is the major determinant of the adult complement of Sertoli cells and whether FSH is obligatory for the initiation, maintenance, and restoration of spermatogenesis is evaluated. The mechanism whereby the circulating concentration of FSH regulates spermatogonial proliferation to dictate the sperm production rate under physiological conditions in the adult is discussed in detail. Inhibin B is the major component of the testicular negative feedback signal governing FSH beta gene expression and FSH secretion, and the evidence for this view is presented. The review concludes with the presentation of a model for the operation of the FSH-inhibin B feedback control system regulating sperm production postpubertally in monkey and man, and with speculation on issues of clinical interest.

Androgen insensitivity syndrome: an immunohistochemical, ultrastructural, and morphometric study

OBJECTIVE

To evaluate the morphometric, immunohistochemical, and ultrastructural lesions of the testes in prepubertal and adult patients with androgen insensitivity syndrome.

METHODS

We examined the testicular biopsy using immunohistochemistry for vimentin, smooth muscle actin, and collagen IV antigens. Quantification of seminiferous tubules and testicular interstitium was performed in prepubertal and adult patients with androgen insensitivity syndrome and results were compared with normal testes from both infants and adults.

RESULTS

The adult testes presented nodular and diffuse lesions that consisted of Sertoli-cell-only seminiferous tubules. Two types of Sertoli cells could be distinguished, namely, immature vimentin-positive Sertoli cells and nearly mature Sertoli cells. In the nodules, the lamina propria was thin and contained a scant number of actin-positive peritubular cells. Leydig cells were hyperplastic. The prepubertal patients showed only diffuse lesions characterized by Sertoli cell hyperplasia, decreased germ cell numbers, and a discontinuous immunoreaction to collagen IV.

CONCLUSIONS

The testicular lesions in androgen insensitivity syndrome are probably caused by primary alterations that begin during gestation. These lesions become progressively more pronounced at puberty, when the nodular lesion pattern (adenomas) is completely developed.

Immunohistochemical and ultrastructural study of Sertoli cells in androgen insensitivity

The ultrastructure of a perfusion-fixed gonad in a case of androgen insensitivity was studied using thin sections and freeze-fracture replicas. The distribution and arrangement of intermediate filaments in Sertoli cells was visualized immunohistochemically using an antibody against vimentin. Leydig cells lacked Reinke crystals, but contained all of the cytoplasmic organelles involved in steroid synthesis and additionally several lysosomes. The basement membrane and the basal lamina of the testicular tubules were considerably thickened. The testicular tubules consisted of gonocytes and Sertoli cells which had an immature nuclear structure, incomplete development of intercellular junctions and a primitive distribution pattern of intermediate cytoplasmic filaments. The previously reported differences in electron density of Sertoli cell cytoplasm are a non-specific feature without significance to Sertoli cell maturation.

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.

Sertoli tumors of the ovary. A clinicopathologic study of 28 cases with ultrastructural observations

The clinical and pathologic features of 28 Sertoli tumors of the ovary are presented. Seventeen of the 18 neoplasms had a functional effect. The effects were hyperestrinism (eight women), isosexual precocious puberty (three girls), virilization (four women), a progestational decidual reaction on the peritoneum (one woman), and a combination of virilizing and estrinizing signs (one woman). There were three histologic patterns: simple tubular, complex tubular, and folliculome lipidique. Two neoplasms recurred, both of which had the distinctive feature of invasion of the supporting stroma by individual and columns of tumor cells in the original tumors. Electron microscopic evaluation of three neoplasms disclosed. Charcot-Böttcher filaments unequivocally identifying the Sertoli differentiation of the predominant cells in the neoplasm. The identification by electron microscopy of a smaller population of cells within the three tumors similar to typical ovarian stromal cells suggests that Sertoli tumors arise from ovarian stromal cells.

Ovarian Sertoli-Leydig cell tumors. A clinical, pathological and ultrastructural study with particular reference to the histogenesis of these tumors

Ovarian Sertoli-Leydig cell tumors are rare, most of them being endocrinologically active and causing virilization. Their histogenesis and nomenclature are still under discussion. Six such tumors were identified in the Laboratory for Histopathology of the University Women's Hospital, Zürich. The clinical data as well as the macroscopic, microscopic and ultrastructural features of these tumors are analysed and discussed. In an attempt to clarify their histogenesis, the ultrastructural features of these tumors have been compared with those of two granulosa cell tumors as well as with those of a testis in a patient with testicular feminization. Our own results and a study of published data suggest that Sertoli-Leydig cell tumors arise from ovarian stroma. Because of their obvious morphological similarities to testicular structures they should be termed "gonadal stromal tumors of android type".

A complete form of testicular feminisation syndrome; a light and electron microscopy study

A case is described of testicular feminisation syndrome in a 19-yr-old patient with a normal female appearance. A laparotomy with removal of the gonads was performed. The latter looked like testes with intraparenchymal nodules. Light and electron microscopy study of these nodules revealed the presence of immature seminiferous-like tubules and of Leydig cell clusters. The tubules were filled with clear Sertoli cells, few degenerative dark cells and scanty spermatogonia. Thin collagen bundles surrounded the tubules and the foci of Leydig cells without any crystals of Reinke. The immaturity of all these cellular components could be connected with a mutation at a repressive locus which could be responsible for the abnormalities observed in the different steps of androgen action at target cell level.

Late discovery of a case of testicular feminisation

The accidental discovery, in an inguinal hernia, of a male gonad in a 67-year-old woman is reported. The association of an unambiguous female phenotype with a purely male karyotype and a male gonad suggests the diagnosis of testicular feminisation. The differential diagnosis, particularly of testicular feminisation with true hermaphroditism, is discussed.

Ultrastructural study of testis in testicular feminization

Testicular tissue was investigated by electron microscopy in a case of testicular feminization. The seminiferous tubules were lined by spermatogonia and by Sertoli cells. Spermatocytic maturation was not observed. Leydig cells were numerous and contained well developed, abundant vesicular smooth-surfaced endoplasmic reticulum and large mitochondria with tubulovesicular cristae. Reinke crystalloids were absent. The ultrastructural findings were consistent with the assumption that Leydig cells were under adequate stimulation and were in a stage of active secretion. Hence, the results seem to indicate that testicular endocrine function was maintained in the studied case.

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.

Freeze-fracture observations on the intercellular junctions of Sertoli cells and of Leydig cells in the human testis

Normal and feminized human testes were examined by means of freeze-fracture. In both cases, the junctional complexes between adjacent Sertoli cells show a unique characteristic feature. Many parallel linear occluding junctions are located circumferentially around the cell surface at the level of the nucleus. They are more than forty in number over one Sertoli cell surface. In the A face, the particles are not prominent on the ridge of the junctions. Instead, they are clearly seen in the center of the groove of the junctions on the B face. Gap junctions consisting of particle aggregation are not found between the Sertoli cells. The gap junctions between the Leydig cells are frequently observed in both normal and feminized testes. They are round or elliptic in contour and about several micrometers in diameter. The particles, about 8 nm in diameter, are closely packed to form a quasi-hexagonal pattern. The pits are found on the B face corresponding to the particle aggregation.