Interstitial Leydig Cell Tumorigenesis-Leptin and Adiponectin Signaling in Relation to Aromatase Expression in the Human Testis

Although epidemiological studies from the last years report an increase in the incidences of Leydig cell tumors (previously thought to be a rare disease), the biochemical characteristics of that tumor important for understanding its etiology, diagnosis, and therapy still remains not completely characterized. Our prior studies reported G-protein coupled estrogen receptor signaling and estrogen level disturbances in Leydig cell tumors. In addition, we found that expressions of multi-level-acting lipid balance- and steroidogenesis–controlling proteins including peroxisome proliferator-activated receptor are altered in this tumor. In order to get deeper into the other molecular mechanisms that regulate lipid homeostasis in the Leydig cell tumor, here we investigate the presence and expression of newly-described hormones responsible for lipid homeostasis balancing (leptin and adiponectin), together with expression of estrogen synthase (aromatase). Samples of Leydig cell tumors (n = 20) were obtained from patients (31–45 years old) and used for light and transmission electron microscopic, western blotting, and immunohistochemical analyses. In addition, body mass index (BMI) was calculated. In tumor mass, abundant lipid accumulation in Leydig cells and various alterations of Leydig cell shape, as well as the presence of adipocyte-like cells, were observed. Marked lipid content and various lipid droplet size, especially in obese patients, may indicate alterations in lipid homeostasis, lipid processing, and steroidogenic organelle function in response to interstitial tissue pathological changes. We revealed significantly increased expression of leptin, adiponectin and their receptors, as well as aromatase in Leydig cell tumors in comparison to control. The majority of patients (n = 13) were overweight as indicated by their BMI. Moreover, a significant increase in expression of phospholipase C (PLC), and kinases Raf, ERK which are part of adipokine transductional pathways, was demonstrated. These data expand our previous findings suggesting that in human Leydig cell tumors, estrogen level and signaling, together with lipid status, are related to each other. Increased BMI may contribute to certain biochemical characteristics and function of the Leydig cell in infertile patients with a tumor. In addition, altered adipokine-estrogen microenvironment can have an effect on proliferation, growth, and metastasis of tumor cells. We report here various targets (receptors, enzymes, hormones) controlling lipid balance and estrogen action in Leydig cell tumors indicating their possible usefulness for diagnostics and therapy.

Leydig cell tumor and hyperplasia: a review

We describe the role of Leydig cells in normal, hyperplastic and neoplastic testis. Recent acquisitions on etiology and pathobiology of Leydig cell proliferations, unusual microscopic presentations and clinical and morphologic features predictive of malignancy are reported.

Urethral stromal tumor with pacemaker cell phenotype

Penile malignancies are rare in developed countries. The authors present a case of a penile urethral mesenchymal tumor occurring in a 51-year-old Caucasian male and displaying light microscopic, immunohistochemical, and ultrastructural features suggestive of a pacemaker cell type, combined with a lack of diagnostic features of any other established tumor category. The immunohistochemical profile was intensely positive for vimentin, PKC theta, and NSE and weakly positive to nonreactive for CD34 and smooth muscle actin, and entirely negative for CD117 (c-kit), S-100, and other markers. C-kit and PDGFRA gene analysis showed no mutations. Electron microscopy revealed tumor cells with plentiful cytoplasm and cytoplasmic processes/filopodia, both filled with intermediate filaments and occasional solitary focal densities. There were also prominent smooth endoplasmic reticulum cisternae, caveolae, neurosecretory granules, particularly concentrated in cytoplasmic processes, and synaptic-type structures. Poorly formed basal lamina, gap junctions, and intercellular collagen aggregates, consistent with skeinoid-type fibers, were also noted. Interstitial cells with potential pacemaker function have been recently described in the lower urinary tract, including the urethra, and this tumor may be related to this cellular phenotype.

Acute action of choriogonadotropin on Leydig tumor cells: qualitative and quantitative transformation of lipid moieties

BACKGROUND

Testicular Leydig cells use either exogenous or de novo synthesized cholesterol as the substrate for the production of testosterone with hormone stimulation. Although the long-term effect of trophic hormones on Leydig cell cholesterol uptake, storage, and deesterification has been well documented, the early effects of the human choriogonadotropin (hCG) on cell cholesterol/lipid distribution are not yet known.

METHODS

Sections of cells treated with hCG for 15 sec to 30 min were examined by electron microscopy (EM) for the surface density of lipid moieties in the cytoplasm. In addition, the time-dependent distribution of lipids within the cytoplasmic inclusions and the ultimate destination of this substrate were evaluated by EM. The results were analyzed with standard morphometric methods.

RESULTS AND CONCLUSION

The surface density of cytoplasmic lipid pools increased significantly within the 15 sec following the exposure of cells to hCG, and it tapered off to the control level in the subsequent 30 min. Such a fluctuation in the amount of cytoplasmic lipids may be due to (1) the quantity of released substrate from the reticular compartment or (2) the rate of its transport across the outer mitochondrial membrane to the inner mitochondrial cytochrome P450 side-chain cleavage, where steroidogenesis begins with the conversion of cholesterol to pregnenolone. These two processes were not quantitatively coordinated in the stimulated cell during the initial 30 min, resulting in a surplus of cytoplasmic lipid pools. To compensate for such uneven metabolic balance, the cell apparently disposed of the excess substrate by a mechanism of molecular regrouping from a micellar configuration to a bilayer structure followed by exocytosis.

ATP and a mitochondrial electrochemical gradient are required for functional activity of the steroidogenic acute regulatory (StAR) protein in isolated mitochondria

The Steroidogenic Acute Regulatory (StAR) protein has been put forth as the rapidly synthesized, cycloheximide-sensitive protein that is required for the transport of cholesterol to the inner mitochondrial membrane and the P450scc enzyme and thereby acutely regulates steroidogenesis in steroidogenic tissues. In this study, several of the factors that may be required for StAR activity were examined using an in vitro system. Lysates from StAR-transfected COS-1 cells were added to mitochondria isolated from MA-10 Leydig tumor cells. Results obtained demonstrated that StAR-containing cell lysate increased steroidogenesis in isolated mitochondria, but failed to do so in the presence of m-CCCP, apyrase, or AMP-PNP, suggesting that StAR function requires ATP hydrolysis as well as an electrochemical gradient for maximal steroidogenic activity.

Leydig cell tumor of the testis: analysis of testosterone production and secretion by three-dimensional histoculture

We treated an 11-year-old boy with a testicular Leydig cell tumor. We analyzed the testosterone production of this tumor by immunolocalization of steroidogenic enzymes and in vitro three-dimensional histoculture. Spermatic venous blood from the tumor bearing testis had noticeably high concentrations of testosterone and androstenedione. The tumor had the characteristic ultrastructural features of steroid producing cells and was immunoreactive for P450scc (side chain cleavage), 3 beta HSD (hydroxysteroid dehydrogenase) and P450c17 (17 alpha-hydroxylase). Three-dimensional collagengel-supported histoculture demonstrated that the tumor tissue in the culture maintained its histologic architecture, expression of steroidogenic enzymes, and secretion of testosterone into the medium for up to 7 days in culture. Histoculture preserved in vitro testosterone production in this case of testicular Leydig cell tumor.

Steroid production after in vitro transcription, translation, and mitochondrial processing of protein products of complementary deoxyribonucleic acid for steroidogenic acute regulatory protein

We have previously demonstrated that steroidogenic acute regulatory protein (StAR) is essential for the rate-limiting step in the acute regulation of steroidogenesis, which is the transport of cholesterol from the outer to the inner mitochondrial membrane. We have hypothesized that this transport occurs as the 37-kilodalton (kDa) precursor form of StAR is imported into the mitochondria and processed to its 30-kDa mature forms. Using an in vitro transcription and translation system in the presence of mitochondria isolated from unstimulated mouse MA-10 Leydig tumor cells, we now directly show that the 37-kDa form is indeed the cytosolic precursor of StAR and can be processed by mitochondria to all four 30-kDa mature forms. To determine the subcellular location of StAR in steroidogenic cells, ultrastructural immunocytochemistry was performed in adrenal zona fasciculata cells using the protein A-gold technique. We show that StAR is associated exclusively with the mitochondria. There, StAR is primarily localized in the intermembrane space and the intermembrane space side of the cristae membrane. StAR was shown to induce steroid production in isolated mitochondria. StAR protein was expressed in COS1 cells and the cell lysate, which was shown to contain abundant levels of StAR by Western blot analysis, was incubated with mitochondria isolated from unstimulated MA-10 cells. In these experiments, StAR increased steroid production by at least 4-fold over control mock-transfected lysate, and this increase was time and dose dependent. Furthermore, the increase in steroid production induced by StAR-containing lysate was not observed when COS1 lysate containing high levels of another mitochondrially imported protein, adrenodoxin, was used. We conclude from these results that in response to tropic hormone stimulation of steroidogenic cells, StAR is synthesized as a 37-kDa precursor, imported into the mitochondria, processed to its 30-kDa mature forms, and localized to the intermembrane space. During import and processing in vitro, StAR induces steroid production in isolated mitochondria in a specific manner.

Topography of the Leydig cell mitochondrial peripheral-type benzodiazepine receptor

Native MA-10 mouse Leydig tumor cell mitochondrial preparations were examined by transmission electron (TEM) and atomic force (AFM) microscopic procedures in order to investigate the topography and organization of the peripheral-type benzodiazepine receptor (PBR). Mitochondria were immunolabeled with an anti-PBR antiserum coupled to gold-labeled secondary antibodies. Results obtained indicate that the 18,000 MW PBR protein is organized in clusters of 4-6 molecules. Moreover, on many occasions, the interrelationship among the PBR molecules was found to favor the formation of a single pore. Taking into account recent observations that the 18,000 MW PBR protein is functionally associated with the pore forming 34,000 MW voltage-dependent anion channel (VDAC) these results suggest that (i) the mitochondrial PBR complex could function as a pore, thus allowing the translocation of cholesterol and other molecules to the inner mitochondrial membrane, and (ii) the native receptor is a multimeric complex of an approximate 140,000 MW composed on an average of five 18,000 PBR subunits, one 34,000 VDAC subunit, and associated lipids.

Intranuclear Reinke's crystals in a testicular Leydig cell tumor diagnosed by aspiration cytology. A case report

Fine needle aspiration cytologic findings in a Leydig cell tumor of the testis are described. Besides the rarity of case reports on fine needle aspiration cytologic diagnosis of this tumor, the present case was of interest because of the finding of numerous intranuclear and intracytoplasmic Reinke's crystals as well as some lying free between the cells. In a few cells the intranuclear crystals were seen to orient themselves in a row, with a nipplelike protrusion of the nuclear membrane as if being pushed by the crystals. Besides the well-formed crystals, many nuclei showed irregular, thin, groovelike spaces that may have been earlier stages of crystal formation. These findings suggested the intranuclear formation of Reinke's crystals. Extranuclear crystals were seen to fuse in pairs and hence to appear thicker than the intranuclear crystals. The crystals lying free between the cells also showed a linear arrangement in places. The crystals were more numerous with May-Grünwald-Giemsa (MGG) staining. Intranuclear crystals were seen only in MGG-stained smears.

A cholesteryl ester hydrolase inhibitor blocks cholesterol translocation into the mitochondria of MA-10 Leydig tumor cells

The present studies describe an unexpected action of a cholesteryl ester hydrolase inhibitor on MA-10 Leydig tumor cells. These studies were initially intended to use the inhibitor, diethylumbelliferyl phosphate, to block cholesteryl ester hydrolysis and, thus, determine the contributions of this form of cholesterol to steroidogenesis and reveal any direct hormone effects on cholesterol esterification. Although this compound acted as an effective inhibitor of the cholesteryl ester hydrolase in intact MA-10 cells, it inhibited steroidogenesis at lower concentrations and to a greater extent than could be explained by simple inhibition of the ester hydrolase enzyme. This compound proved not to be generally toxic, but blocked some process occurring between cAMP formation and cholesterol side-chain cleavage. The diethylumbelliferyl phosphate block of steroidogenesis was readily bypassed by 22-hydroxycholesterol. These data indicated that the compound inhibited cholesterol transport. The lesion in cholesterol transport was not general, but very specific; cholesterol translocation to the mitochondrial site of cholesterol side-chain cleavage was blocked by this organophosphate compound.

Ultrastructure and immunohistochemistry of a fetal-type Leydig cell tumor

A symptomless scrotal mass was removed from a 34-year-old man. The lesion was 7 cm in diameter and it was grossly a hemorrhagic cyst with indurated walls. By light microscopy tumor cell clusters and cords were seen infiltrating the testicle, tunica albuginea, and paratesticular tissue. In the immunohistochemical analysis the tumor cells were immunoreactive with anti-S-100 protein and anticarcinoembryonic antigen, but they did not express cytokeratin or alpha-fetoprotein as tested with paraffin sections. Tumor cell clusters were enveloped by a laminin-positive basement membrane. Electron microscopy revealed abundant smooth endoplasmic reticulum, lipid droplets, and membranous whorls in the cytoplasm. Lamellar whorled bodies were also seen in mitochondria, which contained tubulovesicular cristae. The presence of a well-developed, often multilayered basement membrane was confirmed at ultrastructural level. The activity of 3-beta-hydroxysteroid dehydrogenase suggested that the tumor cells were capable of androgen synthesis. The morphological features are reminiscent of fetal-type Leydig cells and are distinctly different from the Leydig cell tumors described so far.

Benign testicular tumors in children with congenital adrenal hyperplasia

The association between testicular tumors/nodules and congenital adrenal hyperplasia (CAH) has been previously reported. From 1960 to 1989, three patients (13 to 18 years old) with long-standing CAH developed testicular masses. Two patients with 21-hydroxylase deficiency were diagnosed in the neonatal period while one other with 11-hydroxylase deficiency was diagnosed at 3 years of age when he presented with sexual precocity. In all three patients, medical compliance was poor. The testicular masses were bilateral in two patients and unilateral in one, measured 1 to 2 cm, and occupied only the upper half of the testicle. Testicular biopsy specimens were obtained after at least 6 months of evidence of compliance with the adrenocorticotrophic hormone (ACTH) suppressive medication and failure of the nodules to regress. On gross examination the masses appeared to be firm yellow brown nodules. Light microscopy showed interlacing strands, cords, and rests of cells resembling interstitial (Leydig) cells but with no Reinke crystalloids. Electronmicroscopy in all patients showed variable amounts of both smooth and rough endoplasmic reticulum, the later with occasional dilated cisternae. Follow-up ranged from 6 months to 6 years. No further surgical treatment has been necessary. There has been no evidence of recurrence, distant metastases, or secondary malignancies during the time of follow-up. These findings suggest that testicular tumors may develop from chronic excessive ACTH stimulation of a putative pluripotential testicular cell, a Leydig cell, or an adrenal cortical rest. Unlike other testicular tumors these do not require orchiectomy as the initial form of therapy.

Leydig cell tumor of the testis: a case diagnosed by fine-needle sampling without aspiration with histologic, immunohistologic, and electron microscopic analysis

Fine-needle sampling without aspiration was performed in a patient with a testicular mass. The cytologic diagnosis was consistent with Leydig cell tumor. Cytologic features included abundant grey-blue cytoplasms with spherical or oval nuclei in May-Grünwald-Giemsa-stained smears. Intranuclear inclusions were observed but no Reinke's crystals were detected. Histologic findings confirmed the diagnosis and tumor cells were positive for vimentin. Electron microscopic analysis of the tumor showed abundant smooth endoplasmic reticulum and mitochondria with tubulovesicular cristae but no Reinke's crystals.

Cholesterol movement between the plasma membrane and the cholesteryl ester droplets of cultured Leydig tumour cells

The present studies characterize the turnover of plasma membrane cholesterol in MA-10 Leydig tumour cells. Plasma membrane cholesterol of MA-10 cells was slowly internalized and converted into cholesteryl ester. Low-density lipoprotein (LDL) stimulated, in a dose- and time-dependent fashion, plasma membrane cholesterol conversion into intracellular esters. Stimulation of membrane internalization was not simply the consequence of accelerated uptake of membrane with LDL, since binding and internalization of epidermal growth factor and transferrin had no effect on turnover of plasma membrane cholesterol. The protein of LDL is unimportant as well, since delipidated LDL had no effect on membrane turnover. The action of LDL on cholesterol turnover was explained entirely by its contribution to cholesteryl ester stores. The degree of plasma membrane cholesterol internalization and esterification was directly proportional to the size of cellular ester stores.

Malignant Sertoli and Leydig cell tumour in a boar

A rare case of Sertoli and Leydig cell tumour was investigated in a 6-month-old boar. The neoplasm was found in the right testis and had metastasized to the liver, spleen, kidneys and diaphragmatic peritoneum. Metastatic nodules were also present in the tissues near the right testis and some neoplastic cells were present in the superficial inguinal lymph node. The neoplastic cells exhibiting severe pleomorphism were divided into Sertoli and Leydig cell types, although in some sites, it was not possible to classify tumour cells clearly as Sertoli or Leydig in type. In the metastatic lesions there were anaplastic Sertoli cells with abundant collagen fibres. Some neoplastic Sertoli cells and a few neoplastic Leydig cells revealed cytoplasmic reactivity for testosterone. Ultrastructurally, the neoplastic cells were characterized by mitochondria with tubulovesicular cristae, smooth endoplasmic reticulum, membranous structures, lysosomes, lipofuscin granules or lipid droplets.

Steroid biosynthesis in the Sertoli-Leydig cell tumor: effects of insulin and luteinizing hormone

In vitro steroid production by a virilizing Sertoli-Leydig cell tumor of the ovary was studied. For comparison, stromal tissue from the opposite normal ovary was also incubated under similar conditions. The tumor fragments secreted significantly more testosterone (527 +/- 168 versus 48 +/- 29 pg/mg tissue, p less than 0.001), androstenedione (1188 +/- 400 versus 40 +/- 10 pg/mg tissue, p less than 0.001), and dehydroepiandrosterone (419 +/- 132 versus 73 +/- 25 pg/mg tissue, p less than 0.004) than that of normal ovarian stroma. Measurement of steroids in the ovarian venous serum draining the tumor indicated a peripheral ovarian gradient for both delta 4 and delta 5 steroids. Incubation of tumor fragments with luteinizing hormone alone resulted in a significant increase in the secretion of androstenedione and dehydroepiandrosterone (p less than 0.05). Addition of insulin to luteinizing hormone resulted in significantly greater release of androstenedione than that of treatment with luteinizing hormone alone (p less than 0.04). Addition of insulin had no effect on the release of dehydroepiandrosterone. Luteinizing hormone and insulin, either alone or in combination, failed to produce any change in the secretion of testosterone. We conclude that (1) increased testosterone secretion by Sertoli-Leydig cell tumor resulted from increased availability of precursors from both delta 4 and delta 5 pathways; (2) the tumor was responsive to luteinizing hormone with an increase in the secretion of androstenedione and dehydroepiandrosterone; (3) insulin acts synergistically with luteinizing hormone to increase secretion of androstenedione; (4) the tumor has specific binding sites for insulin; and (5) the increased levels of insulin and luteinizing hormone in polycystic ovarian disease may play a role in the pathogenesis of Sertoli-Leydig cell tumor.

Plasma membrane cholesterol: removal and insertion into the membrane and utilization as substrate for steroidogenesis

The plasma membrane cholesterol content of MA-10 Leydig tumor cells is depleted by trophic hormone stimulation and repleted by incubating the cells with low density lipoprotein. The present studies used subcellular fractionation to investigate the membranes involved in steroid hormone synthesis. The results showed that the plasma membrane was the major source of cholesterol substrate and that the cholesterol content changed independently of any mass changes in membrane protein or phospholipid. Membrane phospholipid composition also did not change as membrane cholesterol content decreased or increased, a finding inconsistent with the proposal that phospholipid composition dictates the amount of cholesterol contained in a membrane. The mitochondria of the MA-10 cells were cholesterol rich, containing more cholesterol per unit protein or phospholipid than the plasma membrane. This cholesterol was presumably in the outer mitochondrial membrane, since virtually all of the cholesterol of intact mitochondria was accessible to cholesterol oxidase. Although there was a high concentration of mitochondrial cholesterol, this cholesterol was largely inert as a substrate for steroidogenesis, and plasma membrane cholesterol was incorporated into steroid hormones without ever equilibrating with the mitochondrial cholesterol pool.

Ultrastructure and light microscopical study of a Leydig cell tumor of the testis associated with bilateral gynaecomastia

Light and electronmicroscopic study of a Leydig cell testicular tumor in an 18-year-old male is presented. Bilateral gynaecomastia and normal hormonal blood levels were found. Emphasis on the diagnostic value of electronmicroscopy is remarked upon, based on the following ultrastructural characteristics of the cells; 1) Ovoid shaped nuclei with ondulating contours and dispersed and homogeneous chromatin, 2) Rich agranular endoplasmic reticulum with frequent special modifications, such as membranous whorls with a central cytoplasmic mass or lipid droplets, 3) Numerous mitochondria with occasional tubular cristae, 4) Numerous lipid vacuoles. Other structures also identified in this tumor are Reinke crystalloids, cytoplasmic microbodies, myelin figures, gap-type junctional complexes and paracrystalline inclusions of Payer type E, which are less common.

Epididymal interstitial (Leydig) cell tumors in B6C3F1 mice

Six primary interstitial cell tumors of the epididymis were identified from 46,752 male B6C3F1 mice used in chronic toxicity and carcinogenicity studies. Five of the tumors occurred at the end of 2-year studies; none were attributed to treatment. None of the mice with epididymal tumors had a primary testicular tumor. Histologically, tumors were characterized by a nodular or diffuse proliferation of tumor cells in the epididymal interstitium. Most cells were polygonal with highly vacuolated cytoplasm (vacuolated cells) or eosinophilic cytoplasm (eosinophilic cells). Smaller hyperchromatic cells with scant basophilic cytoplasm (basophilic cells) and cells with yellow-brown pigment characteristic of lipofuscin (pigmented cells) were less common. In each tumor two or more cell types were present. Extension of these tumors through the capsule, invasion of the testis, or metastasis did not occur. By electron microscopy both eosinophilic and vacuolated cell types had a large round or oval nucleus with sparse heterochromatin, abundant mitochondria with tubulovesicular cristae, and frequent desmosome structures between cell membranes. Vacuolated cells contained numerous lipid droplets. Morphological features of the epididymal tumors are similar to those of the testicular interstitial (Leydig) cell tumor in mice and rats.

A stromal Leydig cell tumor of the ovary occurring in a pregnant 15-year-old girl. Ultrastructural findings

The first case of stromal Leydig cell tumor of the ovary occurring during pregnancy is reported. A 15-year-old girl presented in labor at 36.5 weeks of gestation. The tumor mass was obstructing labor and the patient had to be delivered by cesarean section. Unique features of this case included the young age of the patient, the large size of the tumor, and the associated pregnancy. The tumor was encapsulated and showed the typical histologic and ultrastructural features of ovarian stromal Leydig cell tumor. The literature is reviewed, and the differential diagnosis is discussed.

A light and electron microscopical study of intranuclear cytoplasmic invaginations in interstitial cell tumours of dogs

Intranuclear cytoplasmic invaginations, so-called "pseudoinclusions", were seen in all 7 interstitial cell tumours identified among 32 consecutive canine testicular tumours examined. The proportion of cells with intranuclear cytoplasmic invaginations varied from less than 1 per cent to 15 per cent. Similar "pseudoinclusions" were not seen in any other canine testicular tumours examined; this finding might be helpful in differential diagnosis, especially in less differentiated tumours. Histologically, the cytoplasmic invaginations appeared as round, eosinophilic, clearly demarcated intranuclear inclusions and stained with periodic acid-Schiff. Affected nuclei were enlarged. The process of progressive cytoplasmic invaginations into the nucleus and replacement of most of the nuclear volume of the neoplastic interstitial cells with cytoplasmic material was examined by transmission electron microscopy. Two or more cytoplasmic invaginations were sometimes present within a single nucleus. The nuclear membrane could be followed continuously around the cytoplasmic invaginations and nuclear pores were present in the membrane covering invaginations. The invaginations contained smooth and rough endoplasmic reticulum, vesicles, lipid vacuoles, myelin figures and disrupted membranous profiles. Bundles of interwoven cytoplasmic filaments were among the organelles seen in the invaginations in one tumour. Possible reasons for the formation of intranuclear cytoplasmic inclusions are discussed and maintenance of the normal ratio of nuclear surface to nuclear volume is suggested as the mechanism promoting formation of inclusions in interstitial cell tumours.

Biological and biochemical characterization of estrogen-dependent mouse Leydig cell tumors

Leydig cell tumors formed in BALB/c mice were found to be able to be transplanted subcutaneously in the same strain. One of the sublines, called T 22137, showed growth inhibition in response to estrogenization of host mice. The other subline (T 124958-O), which was originally classified as an estrogen-independent line, was observed to contain the low-affinity estradiol binding component in the cytosol fraction. At a later stage of transplantation, however, the growth of this subline was modestly but significantly enhanced by estrogenic stimuli. This alteration was accompanied by appearance of an estrogen receptor-like molecule which was associated with chromatin even in the absence of estrogen stimuli. In the presence of estrogen selection pressure, a new tumor line, designated as T 124958-R, was established, which showed marked estrogen-dependent growth. T 124958-R was found to contain the cytosolic estrogen receptor. The additional difference was that the annulate lamellae were identified only in T 124958-R, but not in T 124958, by electron microscopic studies. The estrogen dependency of T 124958-R was further substantiated by demonstration of an estrogen secretory protein as well as the estrogen-enhanced formation of 5 alpha-steroids. T 22137 showed growth inhibition in tamoxifen-treated mice. The growth of T 124958-R was enhanced by the administration of tamoxifen to mice. This tamoxifen-induced tumor growth was further stimulated by the simultaneous administration of estrogen. These observations would suggest that mouse Leydig cell tumor systems provide us with a valuable model to investigate the influence of estrogen as well as antiestrogen on malignant cells.

Characterization of a feminizing testicular Leydig cell tumor by hormonal profile, immunocytochemistry, and tissue culture

A patient with gynecomastia and a nonpalpable testicular Leydig cell tumor is presented. Estradiol and progesterone levels were elevated whereas serum testosterone was reduced. Following removal of the tumor the hormonal values returned to normal with reduction of gynecomastia. Tumor tissue was maintained in culture for 9 days during which high estradiol levels as well as lesser quantities of testosterone and progesterone were demonstrated in the culture medium. Elevation of progesterone supports a block of 17 alpha-hydroxylase activity caused by increased endogenous estradiol. This is the first case of a cultured feminizing testicular Leydig cell tumor in which hormone production was demonstrated. The freshly removed tumor as well as the cultured tissue material were studied by immunocytochemical methods and biochemical analysis of cytoskeletal proteins. These methods revealed vimentin as the exclusive type intermediate sized filament in both. This is the first demonstration of vimentin in a Leydig cell tumor, in agreement with its occurrence in normal Leydig cells.

Ultrastructural diagnosis in gynaecological pathology

This chapter presents a brief description and discussion of some of the most representative examples of neoplastic and non-neoplastic lesions of the female genital system, in which electron microscopy and ultrastructural analysis may play a significant diagnostic role. The contribution of ultrastructural data in the accurate diagnosis of ovarian neoplasms, particularly the less differentiated ones, is evident and would eventually ensure the proper management of the patients. Similar considerations are explored in the analysis of fine structural studies for the differential diagnosis of lesions of the uterus, vagina and vulva, not only neoplastic but also pseudo-tumoral and inflammatory. In conclusion, electron microscopy represents a very important resource in the modern armamentarium of techniques and approaches available to the general surgical pathologist and the gynaecological pathologist for the diagnostic study of lesions of the female genital system.

Histogenesis, cytodifferentiation, and its subcellular steroidogenic sites in the virilizing ovarian Leydig cell tumor: light microscopic dry-mounting radioautography for [3H]cholesterol and electron microscopic cytochemistry for 3 beta-hydroxysteroid dehydrogenase activity

A case of a virilizing ovarian Leydig cell tumor in a 38-year-old woman with a marked elevated plasma testosterone level was investigated using light microscopic dry-mounting radioautography and electron microscopic cytochemistry. Following a total abdominal hysterectomy and bilateral salpingo-oophorectomy, the plasma testosterone level decreased abruptly. Light microscopic dry-mounting radioautography for [3H]cholesterol showed silver grains localized mainly over the cytoplasm of the neoplastic Leydig cells which were of three different cell types: fibroblast-like cells, Leydig cells (steroid-secreting cells), and transitional cells (partially or incompletely differentiated Leydig cells). Reaction products for 3 beta-hydroxysteroid dehydrogenase activity were localized on the tubular or lamellar cristae and inner membranes of the mitochondria, and on the membranes of smooth endoplasmic reticulum in the transitional cell as well as in the Leydig cell. From these observations, it is suggested that the Leydig cell tumor is derived from the fibroblast-like cell and from the transitional cell, morphologically falling between the fibroblast-like cell and the Leydig cell, has fine structural evidence of steroidogenic activity, and has an ability to secrete testosterone.

Dormancy versus extinction of mouse Leydig cell tumors following endocrine-induced regression

Although a majority of malignant testicular Leydig cell tumors induced in the mouse by chronic estrogenization remain dependent upon estrogen stimulation for growth during early transplant generations, we have observed tumors of two lines, no longer growth dependent upon estrogen, that regressed when hosts bearing palpable tumor grafts were given the same dosage of diethylstilbestrol that had induced the original tumors. Both estrogen-"dependent" and -"responsive" tumors were found to possess a similar estrogen receptor system. The present study compares light and electron microscopic changes occurring during regression and determines the ultimate outcome of the process under these seemingly opposite endocrine conditions. The individual neoplastic cells of the dependent tumors decreased in size, mitochondria with typical tubular cristae rapidly converted to a fully condensed configuration, and endoplasmic reticulum, both rough and smooth, as well as polyribosomes gradually disappeared. A few dormant, RNA-depleted tumor cells always remained, however. After 5 months of dormancy, mitotic activity was induced in many of these cells in 2 to 3 days by reinstituting estrogen administration. This activity began prior to conversion of the mitochondria to an orthodox configuration, to the accumulation of cytochemically demonstrable RNA, or to the appearance of RNA-containing organelles. These observations suggest that at least many of the dormant tumor "stem" cells had been blocked in G2. Contrariwise, the cytoplasmic volumes of the cells of regressing estrogen-responsive tumors increased with a considerable accumulation of lipid droplets, while alterations of the cytoplasmic organelles were much less marked, the mitochondria retaining their pretherapy morphology. Biochemical studies confirmed the fact that, although DNA synthesis ceased within a few days. RNA synthesis was maintained at a near normal level, at least during the first month of tumor regression, during which time the RNA to DNA ratio increased significantly. After 2 months or more of a sustained complete remission, no tumor cells could be found at the transplantation sites, and removing the estrogenic stimulus did not result in tumor regrowth. In short, the treatment had completely obliterated the cancer. It is concluded, therefore, that the molecular events that result in tumor regression from these diametrically opposite endocrine therapies must differ significantly. Both bring about an abrupt cessation of mitotic activity in the neoplastic cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Ovarian sex cord-stromal tumors with bizarre nuclei: a clinicopathologic analysis of 17 cases

Seventeen ovarian sex cord-stromal tumors that contained bizarre nuclei are reported. The patients, two of whom were pregnant, ranged in age from 14 to 72 years (average, 47 years). The tumors, two of which had ruptured, were all Stage Ia. On microscopical examination, all the tumors had areas typical of one of the subtypes of ovarian sex cord-stromal tumors but, in addition, had foci where the cells had enlarged bizarre nuclei. Multinucleated giant cells were present in 12 cases and were of the floret-type in five of them. Apart from the presence of the bizarre nuclei and giant cells, the microscopical appearance and the mitotic rate of the tumors were similar to those of sex cord-stromal tumors in general. Eight tumors were classified as granulosa cell tumors, seven as Sertoli-Leydig cell tumors, and two as thecomas. Eleven patients who have been followed for 3-21 years (average, 9.7 years) postoperatively are alive and free of disease. Two patients have been lost to follow-up, and four have been treated too recently for a meaningful follow-up. The bizarre changes in these tumors resemble those seen in the uterine leiomyoma with bizarre nuclei and, like them, are probably degenerative. Their presence does not appear to alter the prognosis of the underlying tumor in view of the results of this small series.

Ovarian Sertoli-Leydig cell tumor with rhabdomyosarcoma: an ultrastructural study

The clinical and light and electron microscopic findings of a moderately differentiated, virilizing, Sertoli-Leydig cell tumor (SLT) with pleomorphic rhabdomyosarcoma of the ovary are presented. The tumor recapitulates the primitive embryonal testis and rhabdomyogenesis, respectively. The natural history, including pathogenesis, of this peculiar and rare tumor is discussed in the light of the pertinent literature on SLT and ovarian rhabdomyosarcoma. It seems that when rhabdomyosarcoma is a significant or predominant component of SLT, as occurred in this case, the prognosis is poor and is that of rhabdomyosarcoma in general.

Ultrastructure of feminizing testicular Leydig cell tumors

The ultrastructure of a feminizing testicular Leydig cell tumor was analytically compared with that of the five reported feminizing neoplasms and with that of the eight published masculinizing or hormonally inactive tumors. Certain observations were noteworthy but of uncertain significance. In the current case, nuclear outlines tended to be irregular, nuclear pores were relatively few, chromatin was often uniformly dispersed, and nucleoli were frequently multiple. Membranous whorls and "myelin figures" were common. Collectively, the nuclear aberrations were noted only in the two feminizing neoplasms studied by us. Other findings in the present case included abundant endoplasmic reticulum, swollen pleomorphic mitochondria, numerous lysosomes, "dark" and "light" Leydig cell nuclei, and specialized modifications of the plasma membrane. These observations were inconstantly present in the group as a whole, irrespective of hormonal activity. Employing present methods it is not feasible to correlate the fine anatomy of testicular Leydig cell tumors with their capability of hormonal function.

Ultrastructure of a virilizing ovarian Leydig-cell-tumor. Hilar cell tumor

A case of virilizing ovarian hilus cell tumor (Leydig-cell tumor) in a 37 year old female was studied by light and electron microscopy. The ultrastructural features of this rare and almost always benign tumor are compared with those reported in the literature and with findings in normal and neoplastic interstitial cells of the testis. Tubulovesicular hyperplasia and formation of whorl structures of the endoplasmatic reticulum together with the presence of exocytosis vesicles on the cell surface may be the morphological manifestation of endocrine activity of the tumor. The identity of ultrastructural and optical diffraction characteristics of the crystal inclusions in both cells (hilar and testicular interstitial) favours the assumption of an homology of both cells and their neoplasms.

Epidermal growth factor and cyclic AMP stimulation of distinct protein kinase activities in Leydig cell tumor membranes

Epidermal growth factor (EGF) and cyclic AMP were found to stimulate distinct protein kinase activities in plasma membranes prepared from the M5480P murine Leydig cell tumor. EGF stimulated the phosphorylation of two protein bands with apparent molecular weights of 60,000 and 180,000, while cyclic AMP stimulated the phosphorylation of a minor component of molecular weight 220,000. The two types of kinases could also be distinguished on the basis of differential susceptibility to conditions of membrane preparation. These results suggest that EGF stimulates a cyclic AMP-independent protein kinase in murine Leydig cell tumors at the level of the plasma membrane.

Sertoli cell and sertoli-Leydig cell tumors of the ovary. A report of three cases with ultrastructural findings

Three tumors of the ovary containing Sertoli cells were studied by light and electron microscopy. Two of these tumors were well-differentiated neoplasms with epithelial cells often forming tubules. These cells were cylindrically shaped, contained round to oval nuclei and stood on a thin basement membrane. The cytoplasm was fibrillary and showed rough and smooth endoplasmic reticulum, lipid droplets and secretory granules. At the luminal borders the cells were often irregular and displayed apocrine-like activity. Having compared our data with results of studies from the literature of normal Sertoli cells, Sertoli cell adenomas of the testis and cells from other parts of the male reproductive system and those of normal ovarian stroma, we conclude that the Sertoli cell is most probably the cell of origin of these tumors. The third tumor was undifferentiated with a sarcomatoid appearance and contained islands of cartilage, which we consider to be metaplastic.

Malignant Leydig cell tumor: clinical, histologic and electron microscopic features

A 51-year-old man had a malignant Leydig cell tumor of the testis with elevation of serum estrone and androstenedione as well as urine chorionic gonadotropin. The fine structural features of the neoplasm resembled those of nontumorous Leydig cells as well as cells of Leydig cell adenomas, except for, nuclear pleomorphism, the absence of Reinke's crystals and the infrequency of microvilli. The abundance of smooth surfaced endoplasmic reticulum, well-developed mitochondria with tubular and vesicular cristae were regarded as representing ultrastructural expressions of enhanced secretory activity and consistent with the biochemical findings of increased hormonal production by tumor cells. Since Leydig cells have distinct ultrastructural features, ultrastructural investigation represents a valuable tool in establishing the Leydig cell origin of a tumor.

In vivo endocrine studies and morphological features in a case of hilus cell tumor in mesovarium

In a 38-year-old white woman with a virilizing mesovarium hilus cell tumor and polycystic ovaries, serum levels of 13 hormones were measured under different conditions. Endocrine studies showed that testosterone was the principal secretory product of tumor cells. Androstenedione, 17-hydroxyprogesterone, and dehydroepiandrosterone sulfate were normal. Light and electron microscopic investigations of the tumor showed polygonal cells containing intracytoplasmic Reinke crystalloids. Immunoperoxidase studies demonstrated the presence of testosterone within tumor cells.

Composite mucinous ovarian neoplasms associated with Sertoli-Leydig and carcinoid tumors

The authors describe two mucinous ovarian tumors that were hormonally active due to Sertoli-Leydig elements within the septal stroma. Carcinoid was also present in each case. The mesenchymal stromal cells within the septa of the mucinous tumors have undergone neoplastic proliferation with the Sertoli and Leydig differentiations, leading to the formation of arrhenoblastoma. The carcinoid component of these tumors is thought to have originated from argentaffin cells of the "intestinal" mucinous epithelium.

Malignant interstitial cell tumor of the testis

The light microscopic and ultrastructural characteristics of a hormonally active Leydig cell tumor are described. Evidence is adduced that strongly suggests that the Leydig cell tumor was malignant and that functioning metastases were present.

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".

[Leydig cell tumor with pseudoprecocious puberty (author's transl)]

Authors present a case of a Leydig cell testicular tumor in a boy aged three years with a six-month follow-up. This type of tumor which is usually hormone-producing has in children a virilizing effect giving signs of pseudoprecocious puberty. Hormonal tests before and after surgery are described as well as the histological study. The various possibilities of differential diagnosis, treatment and prognosis in the presence of a unilateral testis enlargement in a boy are commented.

Leydig cell tumor with gynecomastia. Report of a case with electron microscopy

A case of Leydig cell tumor is reported and discussed. The tumor, 1.5 cm in diameter, was located in the capsule of the right testis. Gynecomastia present for 3 months was almost absent 4 months postoperatively. Preoperative hormone analysis revealed a low concentration of serum testosterone, which was normalized 1 week postoperatively. In electron microscopic examination, several intracytoplasmic microbody-like structures and 'tigroid' mitochondria were noted. These findings are similar to the three earlier descriptions of Leydig cell tumors.

Leydig cell tumors of the testis

Leydig cell tumors represent approximately one to three percent of all testicular tumors. Whereas in experimental animals predisposing conditions include administration of chemical carcinogens, hormones and heavy metals, environmental or endogenous factors in man are presently unrecognized. Leydig cell tumors do not show preferential lateralization or tendency for bilaterality. The symptoms are related to the local effects or to hormones released into the systemic circulation. Laboratory findings are variable, depending on endocrinological activity. Typical tumors rarely exceed five cm in diameter, are brown on cross section and are composed of polyhedral cells with acidophilic, granular cytoplasm. Ultrastructurally, neoplastic Leydig cells resemble normal Leydig cells. Surgical ablation is curative for benign Leydig cell tumors.

Electron microscopy of a feminizing Leydig cell tumor of the testis

The ultrastructural characteristics of a feminizing interstitial (Leydig) cell tumor of the testis were compared with those of normal Leydig cells and with the findings described in 10 published cases of Leydig cell tumor. The neoplastic Leydig cells superficially resembled normal Leydig cells. Similarities included abundant smooth endoplasmic reticulum, lipid, and microbodies. Contrastingly, Reinke crystalloids and paracrystalline inclusions were absent and lipochrome pigment and lysosomes very rare. The nuclei were large and contained enlarged, often multiple, nucleoli. The nuclear membranes tended to be irregular and undulating. Cytoplasmic membranous whorls and myelin figures were conspicuous. Fairly homogeneous fibrous septa were evident between single and grouped tumor cells. Despite several individual variations, there is a general resemblance between the neoplastic Leydig cells in this patient and those previously reported. No distinguishing ultrastructural characteristics were discerned between feminizing and virilizing Leydig cell tumors.

Effects of a feminizing testicular Leydig cell tumour on nontumorous testicular tissue: an ultrastructual study

The ultrastructural effects of a Leydig cell tumour of the testis on nontumorous testicular tissue have not yet been reported. Described here are the electron microscopic findings in the nonneoplastic testicular tissue of a patient with a feminizing testicular Leydig cell neoplasm. Serial studies were carried out over a period of 31/2 years prior to removal of the tumour. The overall general picture was characterized by progressive degeneration of Leydig cells, cells of the germinal series and Sertoli cells. Concomitantly, there was increasing thickening and fibrosis of the tubular walls. Cytoplasmic focal accumulations of glycogen, increasing with the duration of the disease, were conspicuous in many spermatogonia. All of these alterations are nonspecific and are attributable to adverse endocrine effects introduced by the oestrogen-secreting tumour. They were present bilaterally and were more prominent on the tumour-bearing side. Attention is drawn to the role of artifacts, fixation technique and degenerative processes in the production and appearance of certain ultrastructural findings, such as 'light' and 'dark' cells, myelin figures, membranous whorls and focal glycogen accumulations.

[Leydig cell testicular tumour with an endocrine syndrome. Clinical, biological, ultra-structural and histo-enzymatic study (author's transl)]

With respect to a particularly demonstrative case of Leydig cell tumour with gynaecomastia in a 40 year old man, the authors review the current data in the literature concerning the clinical and biological features and treatment of this tumour. They pay particular attention to the classical anatomo-pathological features, the ultra-structure and the ultrastructural and histo-enzymatic appearances.