Histological evidence of testicular dysgenesis in contralateral biopsies from 218 patients with testicular germ cell cancer

This study was prompted by a hypothesis that testicular germ cell cancer may be aetiologically linked to other male reproductive abnormalities as a part of the so-called 'testicular dysgenesis syndrome' (TDS). To corroborate the hypothesis of a common association of germ cell cancer with testicular dysgenesis, microscopic dysgenetic features were quantified in contralateral testicular biopsies in patients with a testicular germ cell tumour. Two hundred and eighty consecutive contralateral testicular biopsies from Danish patients with testicular cancer diagnosed in 1998-2001 were evaluated retrospectively. Two hundred and eighteen specimens were subsequently included in this study, after 63 patients who did not meet inclusion criteria had to be excluded. The presence of carcinoma in situ (which is believed to originate from transformed gonocytes) was detected in 8.7% of biopsies. The incidence of other dysgenetic features was immature tubules with undifferentiated Sertoli cells, 4.6%; microcalcifications (microliths), 6.0%; and the presence of a Sertoli-cell-only pattern in at least a few tubules, 13.8%. The cumulative incidence of one or more signs of testicular dysgenesis was 25.2%. In a few patients, areas with immature and morphologically distorted tubules were also noted. Spermatogenesis was qualitatively normal in 51.4%, whereas 11.5% had very poor or absent spermatogenesis. It is concluded that microscopic testicular dysgenesis is a frequent feature in contralateral biopsies from patients presenting with testicular germ cell neoplasms of the adolescent and young type. The findings therefore support the hypothesis that this cancer is part of a testicular dysgenesis syndrome. The presence of contralateral carcinoma in situ was higher in the present study than previously reported.     

Sertoli cell types in the Sertoli-cell-only syndrome: relationships between Sertoli cell morphology and aetiology

Histological study of testicular biopsies from infertile men showing Sertoli-cell-only tubules due to hypogonadotropic hypogonadism, cryptorchidism, oestrogen treatment, chemotherapy or Del Castillo's syndrome, revealed four types of Sertoli cells: (1) normal adult mature cells showing an indented nucleus, grossly triangular in shape with a prominent tripartite nucleolus; (2) immature cells with round regularly outlined nuclei and immature cytoplasm; (3) dysgenetic cells showing immature nuclei and a nearly mature cytoplasm with less developed cytoplasmic organelles; and (4) involuting cells with very irregularly outlined nuclei and a mature cytoplasm containing abundant lipid droplets and residual bodies and atypical inter-Sertoli junctional specializations. Testes from men with hypogonadotropic hypogonadism showed only immature Sertoli cells; cryptorchid testes showed dysgenetic cells and occasional normal cells; and after treatment with oestrogens or chemotherapy the testes showed involuting cells and normal cells. The testes of men with Del Castillo's syndrome could be classified into three groups, according to the Sertoli cell type present: mature, dysgenetic and involuting cells. This finding suggests that Del Castillo's syndrome may be due to at least three different aetiologies.     

Testis morphology in patients with idiopathic hypogonadotropic hypogonadism

BACKGROUND: Adult patients with idiopathic hypogonadotropic hypogonadism (IHH) typically present with absent puberty and therefore have prepubertal testes. IHH is recognized as one of the few curable causes of male infertility and is often effectively treated with either gonadotropins or pulsatile GnRH therapy. The objective of this study was to determine the structure of the testis prior to initiation of treatment. METHODS AND RESULTS: Eight adult IHH patients with prepubertal testes (<4 ml), with no previous gonadotropin therapy and with no history of cryptorchidism underwent open bilateral testicular biopsy prior to the initiation of hormonal treatment. The testes of all patients showed seminiferous cords separated by interstitium composed of blood vessels, connective tissue cells and collagen fibres but typical adult Leydig cells were absent. The cords contained only Sertoli cells and early type A spermatogonia. The spermatogonia mostly resided in the centre of the cords and were often large, typical of gonocytes. Sertoli cells appeared immature with ovoid nuclei devoid of infoldings and cytoplasm that lacked polarity. Tight junctional complexes commonly found connecting adult Sertoli cells were lacking. CONCLUSIONS: These results demonstrate that the immature testes from patients with the severe form of IHH possess early spermatogonia that could possibly reinitiate spermatogenesis with appropriate hormone stimulation. Therefore, the immature testis of this IHH subset resembles those of prepubertal boys and may provide important biologic and genetic insights into testicular development.     

Mitotic activity of Sertoli cells in adult human testis: an immunohistochemical study to characterize Sertoli cells in testicular cords from patients showing testicular dysgenesis syndrome

During puberty, normal somatic Sertoli cells undergo dramatic morphological changes due to the differentiation of immature pre-Sertoli cells in functionally active adult Sertoli cells. Sertoli cell maturation is accompanied with loss of their mitotic activity before onset of spermatogenesis and loss of pre-pubertal and occurrence of adult immunohistochemical Sertoli cell differentiation markers. Testes of infertile adult patients often exhibit numerous histological signs of testicular dysgenesis syndrome (TDS) such as microliths, Sertoli cell only (SCO) tubules, tubules containing carcinoma in situ and immature seminiferous tubules (Sertoli cell nodules). Sertoli cell tumours, however, are very rare neoplasms possibly due to the fact that the mechanism and temporal origin of neoplastic Sertoli cells underlying Sertoli cell tumourigenesis still remain unknown. To clarify the state of Sertoli cell differentiation in both immature seminiferous tubules of adult patients with TDS and Sertoli cell tumour, we compared the expression of the Sertoli cell differentiation markers vimentin, inhibin-α, anti-Muellerian-hormone, cytokeratin 18, M2A-antigen, androgen receptor and connexin43 with that of SCO tubules with hyperplasia. In addition, we demonstrated for the first time the existence of proliferating Sertoli cells by Ki67- and PCNA-immunostaining in Sertoli cell nodules of the adult human testis. Our data indicate that mitotically active Sertoli cells in Sertoli cell nodules will be arrested prior to puberty and, contrary to dogma, do not represent foetal or neonatal cells. Since all markers in Sertoli cell nodules revealed a staining pattern identical to that in neoplastic Sertoli cells, but different to that in Sertoli cells of SCO tubules with hyperplasia, it may be speculated that Sertoli cell tumours in adult men may originate from Sertoli cell nodules.     

Pathogenesis of male reproductive tract lesions from gestation through adulthood following in utero exposure to Di(n-butyl) phthalate

Di(n-butyl) phthalate (DBP) acts as an antiandrogen by decreasing fetal testicular testosterone synthesis when male rats are exposed in utero. DBP-exposed male rats develop malformations of the reproductive tract secondary to the reduced fetal androgen levels. However, these malformations and the associated histologic lesions have only been described in adult rats. The objective of this study was to describe the male reproductive tract lesions in fetal, early postnatal, and young adult male rats following DBP exposure in utero. Pregnant Sprague-Dawley rats were exposed to 500 mg/kg/day DBP by gavage on gestation days (GD) 12 to 21. Male reproductive tracts were examined on GD 16 to 21 and on postnatal days (PND) 3, 7, 16, 21, 45, and 70. In the fetal testes, large aggregates of Leydig cells, multinucleated gonocytes, and increased numbers of gonocytes were first detected on GD 17 and increased in incidence to 100% by GD 20 and 21. These lesions resolved during the early postnatal period, while decreased numbers of spermatocytes were noted on PND 16 and 21. On PND 45, there was mild degeneration of the seminiferous epithelium, which progressed to severe seminiferous epithelial degeneration on PND 70. On PND 70, the degeneration was concurrent with ipsilateral malformed epididymides, which caused obstruction of testicular fluid flow and secondary pressure atrophy in the seminiferous tubules. In the fetus, the epididymal lesion was observed as decreased coiling of the epididymal duct. The decreased coiling progressed into the early postnatal period and adulthood, at which time malformed epididymides were apparent. As the animals were only dosed in utero, these findings indicate that DBP can initiate fetal testicular and epididymal changes that may not manifest as clear malformations until adulthood. The pathogenesis of lesion development from the fetus to the adult is important for comparison of antiandrogens with differing modes of action.     

Morphological and histochemical characteristics of the lamina propria in scrotal and abdominal testes from postpubertal boars: correlation with the appearance of the seminiferous epithelium

This study was undertaken to investigate the morphological characteristics and lectin affinity of the testicular lamina propria in healthy boars and in unilateral and bilateral abdominal cryptorchid boars. The lamina propria of scrotal testes from healthy boars and unilateral cryptorchid boars was constituted by an innermost noncellular layer, the basal lamina, and by 2 layers of peritubular cells, each separated by a fibrous layer. The noncellular layers contained collagen fibres and glycoconjugates with abundant N‐acetylgalactosamine, galactose, fucose, N‐acetylglucosamine and neuraminic acid residues. The inner peritubular cell layer was composed of myoid cells, the outer layer of fibroblasts. In the abdominal testes of unilateral and bilateral cryptorchid boars, the lamina propria of nondegenerating and degenerating seminiferous tubules appeared thickened due to an increased content of collagen fibres and glycoconjugates. Glycoconjugates showed decreased amounts of fucose, neuraminic acid and galactose, and increased amounts of N‐acetylglucosamine residues. The basal lamina formed infoldings toward the seminiferous epithelium and contained small cells. Both inner and outer peritubular cells were fibroblasts of immature appearance. In degenerated seminiferous tubules of bilateral cryptorchid boars, the lamina propria was composed of a thickened and collagenised basal lamina, without peritubular cells and with a low content of glycoconjugates. In scrotal testes, therefore, the lamina propria was implicated in tubular contractility and in mediating the communication and the substrate diffusion between seminiferous tubules and interstitial tissue. Cryptorchidism induced morphological and histochemical alterations in the lamina propria of abdominal testes, which may be linked to evidence from other studies of lack of tubular contractility and defective cell–cell communication and substrate diffusion. The severity of these anomalies correlated with the severity of Sertoli cell alterations.     

Cytotoxic phenotype of intra-epithelial lymphocytes in normal and cryptorchid human testicular excurrent ducts

BACKGROUND: Most testicular and epididymal lymphocytes express T-cell markers, but their cytotoxic potential and activation status have not been reported. In this study, distribution of the cytotoxic cells was compared between normal and cryptorchid testes stratified into two groups: the first with complete absence of germ cells [Sertoli cell-only (SCO)] and the second with arrested spermatogenesis (SCA). METHODS: Immunohistochemistry for the T-lymphocyte marker CD3 and cytotoxic markers CD8, TIA-1 and granzyme B was performed on paraffin-embedded sections. RESULTS: The number of CD8+ and CD3+ intra-epithelial lymphocytes (IELs) increased distally throughout the normal epididymis. TIA-1 immunostaining revealed that a significant proportion of IELs exhibited cytotoxic potential, whereas granzyme B staining disclosed a subpopulation of activated cytotoxic lymphocytes (CTLs). TIA-1/CD8 and granzyme B/CD8 double immunostaining revealed that the vast majority of TIA-1+ and granzyme B+ cells were CD8+. The proportion of activated granzyme B+ lymphocytes increased distally throughout the normal epididymis. The number of TIA-1+ and granzyme B+ intra-epithelial and stromal lymphocytes was significantly increased in the normal as opposed to the SCO cryptorchid epididymis and proximal vas deferens. CONCLUSIONS: These results suggest that exposure of the testicular excurrent ducts to spermatozoa or immature germ cells triggers the activation and recruitment of CTLs. Cytotoxic granule effector mechanisms may contribute to the immunological barrier preventing the immune response to spermatozoa in testicular ducts.     

Atypical development of Sertoli cells and impairment of spermatogenesis in the hypogonadal (hpg) mouse

Testes of hypogonadal (hpg) mice show arrested postnatal development due to congenital deficiencies of gonadotrophin-releasing hormone (GnRH) and gonadotrophin synthesis and secretion. Follicle-stimulating hormone (FSH), androgen or oestrogen treatment restore qualitatively normal spermatogenesis in hpg testes. Understanding the cellular and molecular changes accompanying hormone-induced spermatogenesis in hpg mice requires detailed morphological analyses of the germ cells and Sertoli cells in the untreated hpg testis. We compared seminiferous epithelial cytology in adult hpg, immature and adult wild-type mice using unbiased optical disector-based stereology, immunolocalization of Sertoli cell microtubules (MT), espin (a component of the blood-testis barrier), markers of Sertoli cell maturity (p27(kip1) and WT-1), and electron microscopy. Hpg testes had marked reductions in weight, seminiferous cord volume and length, and severe spermatogenic impairment with germ cells per testis < 1% of adult wild-type testes. Sertoli cell nuclei expressed WT-1 in hpg testes, but often were centrally located, similar to 9-14-day-old wild-type testes, and they expressed p27(kip1), indicating that hpg Sertoli cells were post-mitotic. Hpg testes had significantly (P < 0.05) reduced Sertoli cells per testis (0.56 million) compared with 10-day wild-type (1.15 million) and adult wild-type testes (2.06 million). Immunofluorescence labelling of normal adult Sertoli cells showed supranuclear MT columns and basally located espin, but these features were absent in 10-day-old and hpg Sertoli cells. Hpg Sertoli cells showed pleomorphic nuclear ultrastructure with mature-type nucleoli, similar to normal adult-type Sertoli cells, but hpg Sertoli cells exhibited incomplete tight junctions that lacked ectoplasmic specializations. We conclude that in hpg mice, chronic gonadotrophin insufficiency restrains Sertoli cell proliferation and maturation, forming pseudo-adult-type Sertoli cells that are incapable of supporting germ cell proliferation and maturation.     

Hyperplasia and the immature appearance of Sertoli cells in primary testicular disorders

Testicular biopsy specimens from adult patients affected with cryptorchidism, Klinefelter's syndrome, and Del Castillo's syndrome were examined by light and electron microscopy. The study revealed a high proportion of testes showing seminiferous tubules with hyperplasia of Sertoli cells (from 25 to 45 cells per transverse tubular section). These cells had an immature appearance and showed a pseudostratified distribution. The nucleus was round to ovoid and regular in outline, with a smaller nucleolus than that of mature Sertoli cells. The cytoplasm showed less development of the endoplasmic reticulum as well as of the secondary lysosomes and lipid droplets than that in mature Sertoli cells. Characteristic features of these immature Sertoli cells were abundant cytoplasmic microfilaments, elaborate interdigitations between adjacent cells, and extensive tight junctions, from basement membrane to lumen. In the cryptorchid testes, a more immature Sertoli cell was found to constitute the majority of the cells in hypoplastic zones. In Klinefelter's and Del Castillo's syndromes as well as in cryptorchid testes to a lesser degree, a transitional type of cell-from immature to mature-was also observed. These observations suggest that Sertoli cells in these primary testicular disorders reflect a congenital deficiency producing abnormal development.     

Androgen aromatization in cryptorchid mouse testis

Estrogens play an important role in germ cell development. Therefore, we have studied expression patterns of aromatase that converts testosterone into estrogens in 2 recombinant inbred mouse strains that differ in efficiency of spermatogenesis. In order to show whether germ cells are a target for estrogens, estrogen receptors (ER)alpha and beta were localized as well. Adult male CBA and KE mice were made unilaterally cryptorchid to determine alterations in testicular steroidogenesis and spermatogenesis. Differences between control and cryptorchid testes have been studied with respect to (1) cellular sites of aromatase, the enzyme responsible for estrogen formation, (2) the presence of ERalpha and ERbeta in various types of testicular cells, and (3) steroidogenic activity in the testes. Additionally, unilaterally control testes of cryptorchid mice were compared with bilaterally descended testes. Histological or hormonal differences were not found between control testes of cryptorchid and untreated mice. In cryptorchid testes from both strains, degeneration of germ cells was observed as well as a decrease in size of the seminiferous tubules, whereas the amount of interstitial tissue increased, especially in testes of CBA mice. Using immunohistochemistry, aromatase was localized in Leydig cells and germ cells in both control and cryptorchid testes. Sertoli cells were immunopositive in control testes only. In cryptorchid testes of KE mice, aromatase was strongly expressed in spermatids, that were still present in a few tubules. Other cell types in tubules were negative for aromatase. In both control and cryptorchid testes of both mouse strains, ERalpha were present in Leydig cells only, whereas ERbeta were found in Leydig cells and in germ cells in early stages of maturation. In homogenates of testes of CBA control mice, testosterone levels were 3-fold higher than in those of control KE mice, whereas the difference in estradiol levels between both strains was small. Cryptorchidism resulted in decreased testosterone levels and increased estradiol levels. The results of the present study show functional alterations due to cryptorchidism in both mouse strains. Strong aromatase expression in germ cells in control and cryptorchid testes indicates an additional source of estrogens in the testis besides the interstitial tissue and the relevance of estrogen in spermatogenesis.     

Testicular dysgenesis does not affect expression of anti-müllerian hormone by Sertoli cells in premeiotic seminiferous tubules.

Anti-Müllerian hormone (AMH) immunoreactivity was studied on paraffin sections obtained from archival testicular biopsies of 29 children with intersex disorders and of 22 controls. Strong AMH immunoreactivity was observed in Sertoli cell cytoplasm from 8 fetal weeks until puberty. During pubertal maturation, in both normal and intersex patients, AMH expression was present in premeiotic seminiferous tubules, but was no longer detected in neighboring tubules with meiotic development. AMH immunostaining was abolished in the testis of one patient with persistent Müllerian ducts due to a mutation of the AMH gene, but was conserved in the testes of two patients with mutations of the AMH receptor gene. Testicular dysgenesis usually results in sexual ambiguity, with low testosterone and AMH serum levels and persistence of Müllerian derivatives. AMH immunoreactivity was conserved in premeiotic seminiferous tubules of dysgenetic testes, and also in sex-cord cells of a gonadoblastoma. In patients with asymmetric gonadal differentiation, the streak gonad was AMH-negative. In conclusion, secretion of AMH is a constitutive feature of the immature Sertoli cell and its expression is altered only by mutations of the AMH gene, but not by gonadal dysgenesis. The degree of regression of Müllerian ducts and serum AMH levels reflect the number, not the functional value, of Sertoli cells present in the immature testis.     

Inhibin bodies: a new marker for immature Sertoli cells

Nistal M, Pastrián L G, González‐Peramato P & De Miguel M P
(2011) Histopathology 58, 1019–1027
Inhibin bodies: a new marker for immature Sertoli cells Aims: To provide a marker for immature and dysgenetic Sertoli cells which allows easy identification in patients in which Sertoli cell maturation does not take place properly, such as those consulting for cryptorchidism, testicular tumours and infertility. Methods and results: We performed immunohistochemistry against inhibin‐α subunit and the endoplasmic reticulum marker Grp78 in normal human testes from fetal life to adulthood, and in several testicular lesions where Sertoli cell maturation is abnormal. We describe a pattern of inhibin immunostain (inhibin bodies of 2–9 μm in diameter at the Sertoli cells cytoplasm apical pole) in immature and dysgenetic Sertoli cells that facilitates their identification. Inhibin bodies were found in tubules with either no germ cells or only spermatogonia or carcinoma in situ (CIS) and seminoma cells, but not in tubules containing more advanced germ cells. Conclusions: Our data provide a new marker of immature and dysgenetic Sertoli cells. In addition, our data suggest that inhibin bodies represent a slower transit of inhibin through the endoplasmic reticulum, as inhibin bodies were associated with Grp78.     

Ultrastructure of the gonad in the testicular feminization syndrome

The ultrastructural findings on the gonad from a patient with testicular feminization syndrome (TFS) are reported. One gonad was the site of dysgerminoma. The other was a dysgenetic testis composed of seminiferoud and Sertoli cell tubules and ovarian cortical stroma-like tissue. Ultrastructurally the tubules were lined by immature Sertoli cells and cells indistinguishable from dark ovarian stromal cells. Similar and/or identical cells were found in the ovarian-like stroma and in the interstitial tissue between the tubules. There were mature and immature Leydig cells in the intertubular areas. The ovarian cortical-like tissue contained dark and light cells like the normal ovary. Some of the dark cells contained fat droplets like thecoma cells. All these findings point to the dysgenetic nature of the gonad in the TFS as well as the functional activity and or inactivity of certain cells found in it.     

Spermatogonial survival after cryopreservation and short-term orthotopic immature human cryptorchid testicular tissue grafting to immunodeficient mice

BACKGROUND: Fertility preservation has become an urgent clinical requisite for prepubertal male cancer patients undergoing gonadotoxic treatment. As these patients do not yet produce spermatozoa for freezing, only immature tissue is available for storage. We studied the survival and proliferative activity of spermatogonia and Sertoli cells after cryopreservation of cryptorchid testicular tissue pieces followed by xenografting for 21 days. METHODS AND RESULTS: Single pieces of tissue from cryptorchid testes (2-9 mm(3)) of young boys (2-12 years) were cryopreserved, thawed and transplanted into the scrotum of mice. Quantitative morphometric and immunohistochemical techniques were used to evaluate the integrity of the tissue, as well as the survival and proliferative capacity of spermatogonia and Sertoli cells before and after freezing/thawing/grafting. Three weeks after grafting, cryopreserved tissue was removed and analysed. Most of the tubules (88.3%) were intact and there was no fibrosis or sclerosis, 14.5% of the initial spermatogonial population remained, as identified by the MAGE A4 antibody, and 32% of these cells showed proliferative activity evidenced by Ki67, compared to 17.8% before cryopreservation and grafting. The number of Sertoli cells was unchanged and 5.1% were Ki67-positive, compared to none at all before freezing and grafting. CONCLUSIONS: Through our orthotopic xenografting model, we have demonstrated the survival and proliferative activity of spermatogonia and Sertoli cells in cryopreserved immature human cryptorchid tissue. Testicular tissue banking may thus prove to be a promising technique for the preservation of fertility in prepubertal boys undergoing oncological treatments. As the stem cell niche is maintained, the cryopreserved tissue can potentially be used for future autotransplantation. In addition, whole tissue freezing does not exclude alternative clinical uses, including isolated cell transplantation after dissociation, selection and enrichment. However, as this work was done on cryptorchid tissue, studies on normal immature testicular tissue, involving longer grafting periods, are needed to demonstrate a differentiation capacity before clinical implementation. Ethical and safety issues should also be addressed.     

Plurifocal testicular hamartomas and testicular feminization syndrome

We report the case of a 14-year-old girl with a testicular feminization syndrome. The inguinal cryptorchid testis contained plurifocal hamartomas ranging from 0.5 to 1 cm. They were composed of tubules lined by cylindrical Sertoli cells immunoreactive for alpha-inhibin and p30/32(MIC2). The stroma contained few Leydig cells. Ultrastructural study showed tubules with immature Sertoli cells. The testicular feminization syndrome is caused by mutations of the androgen receptor gene. Patients with male genotype 46, XY have a female morphotype with external sexual organs without ambiguity. They have neither uterus nor ovary but two cryptorchid testis in which sex-cord stromal tumors can develop. Their malignant transformation is rare but requires preventive bilateral orchidectomy.     

Granular transformation of Sertoli cells in testicular disorders.

In order to study the granular transformation of Sertoli cells the following testicular specimens were reviewed: 58 postmortem biopsies from 21 children and 37 young adult males with normal histologic pattern; 165 biopsies from prepubertal cryptorchid testes; 38 biopsies and 18 surgical specimens from postpubertal-cryptorchid testes; bilateral biopsies from eight men with Del Castillo's syndrome, 14 men with retractile testes, and five men with obstructive azospermia; 17 bilateral and seven unilateral biopsies from 24 men with varicocele; seven unilateral biopsies plus five surgical specimens from 12 men with male pseudohermaphroditism; one biopsy and one surgical specimen from two men with macroorchidism; and the autopsy specimens from 28 adult men with acquired immunodeficiency syndrome (AIDS). Sertoli cells with eosinophilic granular cytoplasm were found in the testes of one prepubertal and four postpubertal cryptorchid males, two males with Del Castillo's syndrome, two males with retractile testes, four males with varicocele, two male pseudohermaphrodites, two males with macroorchidism, and one male with AIDS and interstitial orchitis. Histochemical and ultrastructural examination of granular Sertoli cells revealed that these cells accumulate secondary lysosomes and show scant cytoplasmic organelles. In the males with varicocele or retractile testes, these lysosomes were probably heterolysosomes that had degraded the germ cells and testicular fluid accumulated in the lumen of the ectatic seminiferous tubules of these testes. A similar mechanism is also probable in the male with interstitial orchitis that had caused germ cell destruction. In the other cases, in which the tubules showed reduced lumen and severe germ cell depletion, the abundant lysosomes are probably cytolysosomes. The development of these cytolysosomes might be related to the Sertoli cell dysgenesis present in these testes.     

Fine structure of boundary tissue of the seminiferous tubules in the scrotal and abdominal testes of naturally unilateral cryptorchid West African dwarf goats

The boundary tissue of the seminiferous tubules in the scrotal and abdominal testes of naturally unilateral cryptorchid West African dwarf goats comprised an inner non-cellular, a middle cellular and peripheral cellular lamellae. In the scrotal testes, these components were compact and their arrangement conformed to that described for other domestic ruminants except that here, the basal lamina associated with the seminiferous epithelium was homogeneous and in tact. Alterations due to cryptorchidism as observed in the contralateral abdominal testes include general loss of compactness due to depletion and disorganization of structural extracellular materials like basal lamina coat of myoid cells and collagen fibrils, the splitting of the basal lamina of the seminiferous epithelium into 8-12 thin layers, poor differentiation of the myoid cells and the accumulation of lipid droplets within their cytoplasm. It is concluded that the normal caprine boundary tissue conforms entirely to the characteristics of 'Type C' category in the existing classification. The ultrastructural alterations due to abdominal retention of the testis resemble the testicular changes ascribed to the disturbance of pituitary-testicular hormonal axis.     

Ultrastructure of gonadoblastoma.

We examined, ultrastructurally, gonadoblastomas from two phenotypic females with a 46,XY and 46,XY/45, XO genotype, respectively. Ultrastructurally, germ cells of gonadoblastoma resembled immature gonocytes; it was not possible to classify them into exact developmental stages given for normal fetal testes or ovaries. In the dysgerminomatous part of the first tumor, germ cells showed ultrastructural signs of differentiation comparable to abortive spermatogenesis as seen in testicular but not ovarian dysgerminosa. The sex cord cells resembled either Sertoli, granulosa, or ovarian stromal cells. The stroma surrounding the epithelial nests resembled the ovarian stroma and contained interstitial cells like Leydig or ovarian hilar cells or both. The epithelial nests of gonadoblastoma were surrounded by laminar multilayered basement membranes. The hyaline masses inside the tumor nests were composed of the same material.