A new crystal-containing cell in human adrenal cortex

Reinke's crystals in perivascular and peritubular Leydig cells of men with non-obstructive and obstructive azoospermia: a retrospective case control study

Aim

To analyze the differences in the population of perivascular and peritubular Leydig cells (LC) and the number of Reinke's crystals (RCs) in the testicles of infertile men with non-obstructive and obstructive azoospermia.

Methods

This retrospective case-control study was conducted on the testicle tissue of infertile men with obstructive (n = 10) and those with non-obstructive azoospermia (n = 100). Stereological analysis was performed on 7-μm paraffin sections. Measurements were carried out by using the Weibel multipurpose test system.

Results

Patients with non-obstructive azoospermia had a higher total/absolute number of LCs in the perivascular space (P = 0.034). In these patients, no significant difference was found in the total and absolute number of RCs between the peritubular and perivascular space. Patients with obstructive azoospermia had around three times higher absolute number of RCs in both the peritubular and perivascular spaces (P = 0.002; P < 0.001) than non-obstructive group.

Conclusion

Our results suggest that in patients with non-obstructive azoospermia LCs migrated or had different densities in the peritubular and perivascular space compared with patients with obstructive azoospermia. Moreover, the lower number of RCs could imply their utilization by LCs in testosterone production.

Immunophenotypic differences between neoplastic and non-neoplastic androgen-producing cells containing and lacking Reinke crystals

We performed a detailed morphologic, immunophenotypic, and endocrine characterization of neoplastic and non-neoplastic lesions of androgen-producing cells known to harbor or lack Reinke crystals (RCs) with an aim to provide further insight into the nature of these cells and crystals. Study cases were selected from the files of participating hospitals and subclassified according to current classifications: 20 with Leydig cell tumors (LCTs), 2 with testicular adrenal rest tumors (TARTs), 2 with testicular tumors of adrenogenital syndrome (TTAGS), and 2 with androgen insensitivity syndrome (AIS). An extensive immunophenotypic panel including markers used in sex cord-stromal cell tumors, androgen hormones, enzymes, and receptors was applied to the cases and 10 non-tumoral adrenal glands. Non-tumoral tissues were scored separately. RCs were present in 90 % of LCT cases and all cases with normal Leydig cells; RCs stained specifically with calretinin and 3β-hydroxysteroid dehydrogenase (3BHSD) and were present only in cells with high concomitant expression of both proteins, a phenotype unique to Leydig cells and LCTs. Leydig cells from AIS cases lack RCs due to decreased expression of 3BHSD. Calretinin is decreased in testicular adrenal-like tumors and absent in normal adrenocortical cells, which explain why they lack RCs. Calretinin expression in androgen-producing cells is independent from androgen receptors and androgen synthesis. RCs represent for the most part, if not exclusively, crystallized forms of a 3BHSD/calretinin complex. Androgen-producing cells containing and lacking RCs differ mainly in the level of expression of these proteins and androgen receptors.

Animal models of adrenocortical tumorigenesis

Over the past decade, research on human adrenocortical neoplasia has been dominated by gene expression profiling of tumor specimens and by analysis of genetic disorders associated with a predisposition to these tumors. Although these studies have identified key genes and associated signaling pathways that are dysregulated in adrenocortical neoplasms, the molecular events accounting for the frequent occurrence of benign tumors and low rate of malignant transformation remain unknown. Moreover, the prognosis for patients with adrenocortical carcinoma remains poor, so new medical treatments are needed. Naturally occurring and genetically engineered animal models afford a means to investigate adrenocortical tumorigenesis and to develop novel therapeutics. This comparative review highlights adrenocortical tumor models useful for either mechanistic studies or preclinical testing. Three model species - mouse, ferret, and dog - are reviewed, and their relevance to adrenocortical tumors in humans is discussed.

Visualization of Reinke's crystals in normal and cryptorchid testis

Within the human testis, Reinke's crystals are found in Leydig cells but their nature and function are poorly understood. The aim of our study was to investigate the properties of Reinke's crystals in man with the normal morphology of the testis (control group) and infertile patients diagnosed with cryptorchidism. 20 biopsies from infertile patients and six biopsies from men with regular spermatogenesis (20-30 years.) were used. Sections of the testis tissue were stained with haematoxylin and eosin and a modified Masson's method. Specimens were observed by bright field, confocal and transmission electron microscopy (TEM). The number of Reinke's crystals in investigated groups was determined applying stereological methods. In both groups, Reinke's crystals were noted within the cytoplasm and nuclei of Leydig cells. Some "free" crystals were found within the interstitial space, outside Leydig cells. Confocal microscopy proved to be very useful in the assessment of the shape and 3D reconstruction of the crystal. TEM analysis confirmed a hexagonal form of the crystal, while crystallographic data on sections of 70-300 nm thickness provided a better insight into the organization of the crystal lattice. Stereological analysis revealed a significant increase in the number of crystals in cryptorchid testes when compared with controls. Increased number of crystals in cryptorchid specimens leads to the assumption that the prolonged exposure to higher (abdominal) temperature might stimulate enzymes involved in the synthesis of the proteins of the crystal. However, the exact molecular nature of the crystal lattice remains in both normal and cryptorchid testis obscure.

Gonadectomy-induced adrenocortical neoplasia in the domestic ferret (Mustela putorius furo) and laboratory mouse

Sex steroid-producing adrenocortical adenomas and carcinomas occur frequently in neutered ferrets, but the molecular events underlying tumor development are not well understood. Prepubertal gonadectomy elicits similar tumors in certain inbred or genetically engineered strains of mice, and these mouse models shed light on tumorigenesis in ferrets. In mice and ferrets, the neoplastic adrenocortical cells, which functionally resemble gonadal steroidogenic cells, arise from progenitors in the subcapsular or juxtamedullary region. Tumorigenesis in mice is influenced by the inherent susceptibility of adrenal tissue to gonadectomy-induced hormonal changes. The chronic elevation in circulating luteinizing hormone that follows ovariectomy or orchiectomy is a prerequisite for neoplastic transformation. Gonadectomy alters the plasma or local concentrations of steroid hormones and other factors that affect adrenocortical tumor development, including inhibins, activins, and Müllerian inhibiting substance. GATA-4 immunoreactivity is a hallmark of neoplastic transformation, and this transcription factor might serve to integrate intracellular signals evoked by different hormones. Synergistic interactions among GATA-4, steroidogenic factor-1, and other transcription factors enhance expression of inhibin-alpha and genes critical for ectopic sex steroid production, such as cytochrome P450 17alpha-hydroxylase/17,20 lyase and aromatase. Cases of human adrenocortical neoplasia have been linked to precocious expression of hormone receptors and to mutations that alter the activity of G-proteins or downstream effectors. Whether such genetic changes contribute to tissue susceptibility to neoplasia in neutered ferrets and mice awaits further study.

Staining of the Reinke crystalloids in the human testis--re-evaluation study

Reinke crystalloid (CR)s are rod or corn shaped structures present in the interstitial cells (Leydig cell) of human testis. Due to existing controversies and because of their importance in histological studies, we decided to reevaluate their staining behavior with various dyes. Earlier it has been shown that hematoxylin and eosin dyes do not stain CRs even though their protein nature remains undisputed. In the present study, sections of testicular tissues embedded in glycol-methacrylate (GMA) showed that hematoxylin binds to CRs non-specifically and eosin stains them specifically. The reasons for stainability and/or non stainability of CRs with hematoxylin, eosin and other dyes are discussed.

Mouse strain susceptibility to gonadectomy-induced adrenocortical tumor formation correlates with the expression of GATA-4 and luteinizing hormone receptor

Certain inbred strains of mice, including DBA/2J, develop adrenocortical tumors in response to gonadectomy. Spindle-shaped cells with limited steroidogenic capacity, termed A cells, appear in the subcapsular region of the adrenal gland, followed by sex steroid-producing cells known as B cells. These changes result from unopposed gonadotropin production by the pituitary, but the adrenocortical factors involved in tumorigenesis have not been characterized. GATA-4, a transcription factor normally expressed in fetal, but not adult, adrenocortical cells, was found in neoplastic cells that proliferate in the adrenal cortex of gonadectomized DBA/2J mice. GATA-4 mRNA was detected in the adrenal glands of female mice 0.5 months after ovariectomy and reached a maximum by 4 months. Castrated male mice developed adrenocortical tumors more slowly than gonadectomized females, and the onset of GATA-4 expression in the adrenal was delayed. In situ hybridization and immunohistochemistry revealed GATA-4 mRNA and protein in A and B cells, but not in normal adrenocortical cells. mRNA encoding another factor associated with adrenocortical tumorigenesis, LH receptor (LHR), was detected in A and B cells. In addition, transcripts for P450 17 alpha-hydroxylase/C17-C20 lyase, an enzyme essential for the production of sex steroids, and inhibin-alpha were found in B cells. Unilateral ovarian regeneration, a phenomenon known to occur in gonadectomized mice, was observed in a subset of DBA/2J mice undergoing complete ovariectomy. In these animals, adrenocortical tumor progression was arrested; A cells and GATA-4 expression were evident, but there was no expression of LHR or P450 17 alpha-hydroxylase/C17-C20 lyase. Strain susceptibility to adrenocortical tumorigenesis (DBA/2J >> FVB/N) correlated with the expression of GATA-4 and LHR, implicating these factors in the process of adrenocortical neoplasia in response to continuous gonadotropin stimulation.

Electron microscopy what Izzits revisited: an ultrapath VI quiz

Thirteen cases of various natures, selected from a collection shown and discussed at Ultrapath VI, are presented in quiz format for recognition or diagnosis.

Leydig cells within the aspermatogenic seminiferous tubules

Cells identical to Leydig cells were found within a peritubular boundary layer and even inside a basal lamina of seminiferous tubules in three male patients (two with inguinal cryptorchism and one with infertility). The seminiferous tubules of all patients showed a moderate to marked thickening of the boundary layer and a complete loss of spermatogenic cells. The "ectopic Leydig cells" were characterized by the presence of Reinke crystals or an extensively developed smooth endoplasmic reticulum. These cells were believed to have differentiated in situ from myoid cells within the boundary layer and also to have invaded from the interstitial tissue in the form of mature Leydig cells. The occurrence of ectopic Leydig cells appeared to parallel the extent of loss of the Sertoli cells and also that of the thickening of the boundary layer. The functional significance of the ectopic occurrence might be implicated in the impaired spermatogenesis.

Occurrence of cells containing paracrystalloid material in the intestinal lamina propria of the hibernating bat Myotis lucifugus

A light and electron microscope study of the small intestine of the little brown bat, Myotis lucifugus, was carried out at several stages in the animal's annual life cycle. An unusual morphological observation was the presence of cells in the lamina propria of the small intestine which were packed with a conspicuous basophilic granular material that appeared crystalline. Moreover, such cells were present only during the hibernation period and were therefore called "hibernation crystalloid" (HC) cells. By light microscopy, the crystal-like material was not sudanophilic, did not stain for nucleic acids, and did not contain acid phosphatase; it did show reactivity when stained by the periodic acid-Schiff procedure. By electron microscopy, the crystal-like material was found to be present in smooth, membrane-enclosed vacuoles along with an amorphous, dense granular substance. The crystalline material occasionally formed rigid-appearing rods that reached lengths of 10 microns. The crystal-containing cells were contacted by axonal varicosities. It is suggested that these innervated HC cells represent a unique cell type with a gastrointestinal function, yet to be determined, that may be related to hibernation.

Crystalloid formation in Leydig cells of rats (Rattus fuscipes). An ultrastructural and hormonal study

The ultrastructure of Leydig cells in a seasonally breeding rodent, Rattus fuscipes, was studied in the breeding and non-breeding season and compared with Leydig cell morphology after suppression of gonadotrophin secretion induced by hypophysectomy or chronic administration of testosterone. Serum luteinizing hormone (LH) and testosterone (T) were measured and in-vitro T production by testes was assessed by stimulation with human chorionic gonadotrophin (hCG). In non-breeding wild-trapped rats and rats with experimental suppression of gonadotrophins, the Leydig cells were atrophied and exhibited variable amounts of cytoplasmic lipid and crystalloid inclusions, the latter commonly dominating the cytoplasmic area. Compared with fertile rats, serum LH and hCG-stimulated T production of experimentally regressed rats was significantly reduced, confirming structural features indicative of Leydig cell inactivity. Atrophy of Leydig cell nuclei was accompanied by the formation of unusual intranuclear vesicles sometimes containing small crystalloids. Ultrastructural analysis suggested transfer of the vesicles to the cytoplasm where their unification gave rise to much larger crystalloid bodies. Crystalloids occurred when serum LH was depressed and with either full (T treatment) or arrested spermatogenesis (hypophysectomy) suggesting that their formation is governed by pituitary function and is not dependent upon the degree of spermatogenic activity.

Intra-adrenal hepatic heterotopia

The second case of intra-adrenal hepatic heterotopia is described in a normally structured male fetus stillborn at 26 weeks of gestation. The liver nodule, incidentally found in a random histological section of the right adrenal, was not encapsulated and blended with the adjacent fetal cortex. It consisted of cords of immature hepatocytes with abundant sinusoids and widespread hemopoiesis. Abnormalities included absence of a hexagonal pattern, incomplete portal tracts with dilated veins only, lack of bile ducts and canaliculi, and apparent failure of bile formation and glycogen deposition.

An adrenal adenoma causing virilization of mother and infant

A right adrenal androgen-producing adenoma was identified by CT scanning in a 33-year-old woman after delivery of an otherwise-normal, virilized female infant. Despite clinical evidence of mild chronic androgen excess, maternal reproductive function was normal. Post-partum studies showed 2-5-fold excess in maternal plasma testosterone, androstenedione and dehydroepiandrosterone-sulphate; urinary androgen metabolites were increased 3-10-fold. Androgen production from the tumour increased acutely in response to hCG administration; after removal of the tumour, androgen levels were normal and showed negligible responses to hCG. These findings lead us to speculate that endogenous chorionic gonadotrophin may have led to augmented androgen production from the adrenal tumour during pregnancy, causing fetal virilization as previously described in patients with ovarian tumours. This study demonstrates that CT scanning can be valuable in distinguishing between adrenal and ovarian androgen-producing tumours, a distinction which is often unreliable when based on physiological manipulations of hormone secretion.

Appearance and disappearance of tubular paracrystalline structures in somatotrophs and lactotrophs during the annual life cycle of the bat (Myotis lucifugus)

The fine structure of the endocrine (granulated) cells of the adenohypophysis of the bat was examined at different periods of the annual life cycle. During the active homeothermic period (early spring until late summer) the endocrine cells were heavily granulated, and evidence of granule release was commonly seen. At this time, but not at other times (hibernation and arousal), prominent paracrystalline structures were numerous and transiently appeared in the cytoplasm of acidophils (apparently both lactotrophs and somatotrophs) but not in the cytoplasm of basophils. These paracrystalline bodies were composed of densely packed, parallel arrays of tubules. The paracrystalline structures in lactotrophs differed in size, shape, and the pattern of arrangement of component tubules from those of somatotrophs. During hibernation no evidence of exocytosis was seen, and secretory granules accumulated in the cytoplasm. Prior to arousal, secretory granules were removed by autophagy.

Leydig-like cells in the adrenals of a woman with ectopic ACTH syndrome

A 36 year old woman with hypercorticism and markedly elevated blood ACTH levels underwent pituitary ablation because of suspected hypophysial Cushing's disease. Since no adenoma was detected in the anterior lobe and the hypercorticism persisted, a bilateral adrenalectomy was performed. Four months later lymph node and mediastinal metastases of an anaplastic small cell carcinoma, with the presence of argyrophil granulation, as well as immunoreactive 19-39ACTH, beta-LPH and alpha-endorphin, were found. The primary site of ectopic ACTH production was not revealed. A light and electron microscopic study of the adrenals, in addition to cortical hyperplasia, disclosed numerous small cells associated with nonmyelinated sympathetic nerve fibers and containing cytoplasmic inclusions indistinguishable from Reinke crystals. The Leydig-like cell-nonmyelinated nerve complexes, noted in both the adrenal cortex and medulla, showed perivascular localization, and their morphologic features were similar to those of hilus cells of the ovaries or extraglandular Leydig cells of the testis. The underlying mechanism accounting for the development of Leydig-like cells remained obscure; cytodifferentiation from pluripotent mesenchymal cells, possibly mediated by secretory products of sympathetic nerve fibers, may provide an explanation for their formation.

Ultrastructural and enzyme histochemical study of ovarian hilar cells in women and their relationships with sympathetic nerves

The ultrastructure of normal ovarian hilar cells, both during the reproductive era and after the menopause, shows evidence of steroid hormone synthesis. In this respect these cells are very similar to Leydig cells in that they contain mitochondria with a dense matrix, a highly developed smooth endoplasmic reticulum, Reinke crystals, and microcystalline inclusions. The latter are much more numerous than in the normal testis. Their enzymatic activities are quite similar to those of Leydig cells. Ovarian hilar cells seem to originate from progressive metamorphosis of fibroblastic cells under the induction of sympathetic nervous structures. Their relations with hilar nerves are of three types: simple direct membrane contact without a Schwann cell sheath, intimate intracytoplasmic relationships, and specialized contacts, which are comparable to a synapse.

Ectopic Leydig cells in a seminiferous tubules of an infertile human male with a chromosomal aberration

A case of a human male infertility with chromosomal aberration is reported. The patient showed neither mental retardation nor physical abnormalities except that the testes were somewhat small and soft. Plasma follicle stimulating hormone and luteinizing hormone were 49.0 and 19.0 mIU/ml. Plasma testosterone was 2.6 ng/ml. Karyotype was considered to be 46 XY q-, long arms of the Y chromosome being deleted. Histological features of the testis were peculiar. Seminiferous tubules were small and devoid of spermatogenic cells, consisting only of Sertoli cells. Peritubular boundary layer of the tubules showed a marked increase in width due to the increase of collagen fibers. The base of some Sertoli cells was seen to protrude into the thickened peritubular boundary layer or, though rare, into the interstitial space. Unusual cells which had a round vesicular nucleus and abundant, dense cytoplasms also occurred in the boundary layer of most tubules. These cells were identified as Leydig cells because of an extensively developed smooth endoplasmic reticulum in their cytoplasm, although they lacked Reinke's crystals. These ectopic Leydig cells sometimes lay in direct contact with Sertoli cells in the seminiferous tubule.

Stereological analysis of Reinke's crystals in human Leydig cells

Reinke's crystals in human Leydig cells were analyzed stereologically to assess their functional role. Testicular tissues were taken from seven older men (57--82 years old) with prostatic carcinoma and also from seven younger men (26--38 y.o.) complaining of male infertility. Sections 0.5 micrometer thick, stained with toluidine blue or Heidenhein's iron-hematoxylin were examined by a point-counting method and with a Particle Measurement Computor System (IIMC). When the patients were grouped by age, the mean crystal volume, the number of crystals per cell, the volume of crystals per cell and the volume ratio of crystals to cell were significantly larger in the older age group than in the younger age group. In particular, the latter three variables correlated well with the age of subjects, with correlation coefficients of r = 0.66--0.85. On the other hand, none of these variables had any correlation with the concentration of plasma testosterone. These results indicate that Reinke's crystals can be considered as degenerative products in cell life but not as facultative constituents for testosterone production.

Crystalline structures in human pancreatic beta cell adenoma

An electron microscopic observation on a pancreatic tumor removed from a 34-year-old woman revealed the fine structural morphology of a functional beta cell adenoma. Characteristic PAS positive crystalline structures were frequently observed in the cytoplasm of the tumor cells. They were not bounded by a membrane and had a rectangular or irregular hexagonal shape. Highly regular patterns were seen as such as lattice or honeycomb and parallel ripple structures. They are similar to the Reinke's crystal or crystalline structures reported in human hepatocytes suffering from several different diseases and considered as a protein-carbohydrate complex. Occasionally, small paracrystalline structures appeared to indicate an immature type of these structures in the opaque fine fibrillar mass. Crystalline or paracrystalline structures were not detected in the normal pancreatic tissue removed with the tumor from the patient.

Membrane unbound crystals in pancreatic acinar cells of the mouse

The exocrine pancreas of normal mice was investigated electron microscopically. The crystals were encountered in the basal cytoplasm of the acinar cells. They exhibited usually rectangular or rhomboidal profiles, measuring less than 5 mum in length and more than 0.1 mum in width. The matrices of these crystals displayed substructures of parallel dense linear pattern. The center-to-center distances between the dense lines were 100 similar to 150 A. The crystals were not limited at their surface by any membrane, but rather were densely circumscribed or sporadically surrounded by ribosomes. Filaments were interposed between ribosomes and crystal matrices and also between matrices of abutting crystals. The significance of the close relation of ribosomes to crystals was discussed.