The Administration of Cortisol Induces Female-to-Male Sex Change in the Protogynous Orange-Spotted Grouper, Epinephelus coioides

In this study, we injected cortisol into the protogynous orange-spotted grouper (Epinephelus coioides) to investigate the role of this hormone in sex change. Following injection, we evaluated gonadal changes, serum levels of steroid hormones, and sex-related gene expression during the processes of cortisol-induced sex change and cortisol withdrawal in the orange-spotted grouper. Cortisol treatment caused the degeneration of oocytes and induced sex change in a dose-dependent manner. Over the long-term, we observed a significant increase in serum 11-ketotestosterone (11-KT) levels in all cortisol-treated groups, although levels of 17β-estradiol did not change significantly. Consistent with the elevation of serum 11-KT levels, the expression of genes related to testicular development was also significantly up-regulated in the cortisol-treated groups. Based on our results, we propose that cortisol may trigger masculinization by inducing the synthesis of 11-KT and by directly activating the expression of sex-related genes. Furthermore, we found that cortisol-induced sex change was not permanent and could be reversed after the withdrawal of cortisol treatment.

Prenatal Androgenization of Ewes as a Model of Hirsutism in Polycystic Ovary Syndrome

The main clinical feature associated with hyperandrogenism in polycystic ovary syndrome (PCOS) in humans is hirsutism, where hair increases its length, pigmentation, and particularly its diameter. Currently, it is not known whether PCOS animal models also exhibit changes in the hair. Therefore, the aim of this study was to explore the wool characteristics in sheep prenatally androgenized (PA) with testosterone propionate. After 4 and 13 months of life, wool was collected from the top of the shoulder of both females and males (both androgenized and controls). The offspring sheep were followed for up to 19 months of life to evaluate testosterone and androstenedione serum levels by ultra-high-performance liquid chromatography-tandem mass spectrometry, determine insulin and glucose response to intravenous glucose tolerance test, and address estrus cyclicity during the second breeding season. PA male animals showed a reduction in wool fiber diameter at 4 months of age compared with controls (P = 0.02) but not at 13 months, whereas PA females showed increased hair diameter at 13 months (P = 0.002), with no difference at 4 months. No substantial changes in other hair parameters (length, color, and medullation) were identified. In addition, increased levels of serum testosterone were observed in PA female sheep compared with controls at 12 months (P = 0.03). Our results indicate for the first time, to our knowledge, that changes in wool fiber diameter observed in PA ewes replicate, at the translational level, the increase in hair diameter in hirsute women with PCOS.

Germ cell depletion in zebrafish leads to incomplete masculinization of the brain

Zebrafish sex differentiation is under the control of multiple genes, but also relies on germ cell number for gonadal development. Morpholino and chemical mediated germ cell depletion leads to sterile male development in zebrafish. In this study we produced sterile males, using a dead end gene morpholino, to determine gonadal-brain interactions. Germ cell depletion following dnd inhibition downregulated the germ cell markers, vasa and ziwi, and later the larvae developed as sterile males. Despite lacking proper testis, the gonadal 11-ketotestosterone (11-KT) and estradiol (E2) levels of sterile males were similar to wild type males. Qualitative analysis of sexual behavior of sterile males demonstrated that they behaved like wild type males. Furthermore, we observed that brain 11-KT and E2 levels in sterile males remained the same as in the wild type males. In female brain, 11-KT was lower in comparison to wild type males and sterile males, while E2 was higher when compared to wild type males. qRT-PCR analysis revealed that the liver transcript profile of sterile adult males was similar to wild type males while the brain transcript profile was similar to wild type females. The results demonstrate that proper testis development may not be a prerequisite for male brain development in zebrafish but that it may be needed to fully masculinize the brain.

Androgen production in pediatric adrenocortical tumors may occur via both the classic and/or the alternative backdoor pathway

Children with adrenocortical tumors (ACTs) often present with virilization due to high tumoral androgen production, with dihydrotestosterone (DHT) as most potent androgen. Recent work revealed two pathways for DHT biosynthesis, the classic and the backdoor pathway. Usage of alternate routes for DHT production has been reported in castration-resistant prostate cancer, CAH and PCOS. To assess whether the backdoor pathway may contribute to the virilization of pediatric ACTs, we investigated seven children suffering from androgen producing tumors using steroid profiling and immunohistochemical expression studies. All cases produced large amounts of androgens of the classic and/or backdoor pathway. Variable expression of steroid enzymes was observed in carcinomas and adenomas. We found no discriminative pattern. This suggests that enhanced androgen production in pediatric ACTs is the result of deregulated steroidogenesis through multiple steroid pathways. Thus future treatments of ACTs targeting androgen overproduction should consider these novel steroid production pathways.

Androgen Dependent Mammary Gland Virilism in Rats Given the Selective Estrogen Receptor Modulator LY2066948 Hydrochloride

A selective estrogen receptor modulator (SERM) is a nonsteroidal compound with tissue specific estrogen receptor (ER) agonist or antagonist activities. In animals, SERMs may produce morphologic changes in hormonally-sensitive tissues like the mammary gland. Mammary glands from female rats given the SERM LY2066948 hydrochloride (LY2066948) for 1 month at ≥ 175 mg/kg had intralobular ducts and alveoli lined by multiple layers of vacuolated, hypertrophied epithelial cells, resembling in part the morphology of the normal male rat mammary gland. We hypothesized that these SERM-mediated changes represented an androgen-dependent virilism of the female rat mammary gland. To test this hypothesis, the androgen receptor antagonist flutamide was co-administered with LY2066948 (175 mg/kg) to female rats for 1 month. Female rats given SERM alone had hyperandrogenemia and the duct and alveolar changes described here. Flutamide cotreatment did not affect serum androgen levels but completely blocked the SERM-mediated mammary gland change. In the mouse, a species that does not have the sex-specific differences in the mammary gland observed in the rat, SERM treatment resulted in hyperandrogenemia but did not alter mammary gland morphology. These studies demonstrate that LY2066948 produces species-specific, androgen-dependent mammary gland virilism in the female rat.

Pubertal outcome in a female with virilizing adrenocortical carcinoma

Adrenocortical tumors are neoplasms that rarely occur in pediatric patients. Adrenocortical carcinoma (ACC) is even more uncommon, and is an aggressive malignancy with 5-year survival of 55% in a registry series. There is a lack of information on long-term endocrine outcome in survivors. We describe a 10-year follow-up in a patient who presented at 3 years 5 months with a 1-year history of axillary odor and 6 months' history of pubic hair development with an increased clitoral size. Androgen levels were increased and a pelvic sonogram revealed a suprarenal mass of the left kidney. The tumor was successfully removed. At 6 years 11 months, androgen levels increased again. Workup for tumor recurrence was negative and the findings likely represented early adrenarche. The patient had menarche at an appropriate time and attained a height appropriate for her family.

Virilizing sclerosing-stromal tumor of the ovary in a young woman with McCune Albright syndrome: clinical, pathological, and immunohistochemical studies

CONTEXT

McCune-Albright syndrome (MAS) is characterized by polyostotic fibrous dysplasia, café-au-lait skin pigmentations, and gonadotropin-independent sexual precocious puberty, resulting from a somatic postzygotic activating mutation of the GNAS1 gene.

SETTING

We report a virilizing sclerosing-stromal tumor of the ovary in a young female with MAS.

PATIENT

She presented polyostotic fibrous dysplasia of the left upper and lower limbs and a café-au-lait skin spot in the posterior area of the neck. She had a history of precocious puberty, diagnosed at the age of 6 years and treated with cyproterone acetate until the age of 10 years; then she developed central puberty with severe oligomenorrhea. At the age of 23 years, she was hospitalized for a virilization syndrome including hirsutism, acne, deepening of the voice, amenorrhea, and clitoromegaly. Serum levels of T were dramatically increased (1293 ng/dl; normal range, 10-80). The abdominal computed tomography scan revealed a solid mass located on the left ovary.

INTERVENTION

An ovariectomy was performed, and histological examination revealed a sclerosing-stromal tumor with pseudolobular pattern.

RESULTS

Immunohistochemical studies revealed that the tumor cells expressed all steroidogenic enzymes involved in androgen synthesis. Molecular analysis revealed that ovarian tumor cells harbored the Arg 201 activating mutation in the GNAS1 gene. After surgery, T levels returned to normal, the patient retrieved a normal gonadal function, and she was able to become pregnant.

CONCLUSION

This observation extends the clinical spectrum of ovarian pathology of women with MAS. However, the mechanisms causing this ovarian tumor remain unclear, even if the gsp oncogene has been implicated in the pathogenesis of some gonadal tumors.

Pubertal androgenization and gonadal histology in two 46,XY adolescents with NR5A1 mutations and predominantly female phenotype at birth

OBJECTIVE

Most patients with NR5A1 (SF-1) mutations and poor virilization at birth are sex-assigned female and receive early gonadectomy. Although studies in pituitary-specific Sf-1 knockout mice suggest hypogonadotropic hypogonadism, little is known about endocrine function at puberty and on germ cell tumor risk in patients with SF-1 mutations. This study reports on the natural course during puberty and on gonadal histology in two adolescents with SF-1 mutations and predominantly female phenotype at birth.

DESIGN AND METHODS

Clinical and hormonal data and histopathological studies are reported in one male and one female adolescent with, respectively, a nonsense mutation (c.9T>A, p.Tyr3X) and a deletion of the first two coding exons (NCBI36/hg18 Chr9:g.(126306276-126307705)_(126303229-126302828)del) of NR5A1, both predicted to fully disrupt gene function.

RESULTS

LH and testosterone concentrations were in the normal male range, virilization was disproportionate to the neonatal phenotype. In the girl, gonadectomy at 13 years revealed incomplete spermatogenesis and bilateral precursor lesions of testicular carcinoma in situ. In the boy, at the age of 12, numerous germ cells without signs of malignancy were present in bilateral testicular biopsy specimen.

CONCLUSIONS

In SF-1 mutations, the neonatal phenotype poorly predicts virilization at puberty. Even in poorly virilized cases at birth, male gender assignment may allow spontaneous puberty without signs of hypogonadotropic hypogonadism, and possibly fertility. Patients with SF-1 mutations are at increased risk for malignant germ cell tumors. In case of preserved gonads, early orchidopexy and germ cell tumor screening is warranted. The finding of premalignant and/or malignant changes should prompt gonadectomy or possibly irradiation.

Sertoli-Leydig cell tumor of the ovary--morphological and immunohistochemical analysis

Sertoli-Leydig cell tumor is a rare and usually unilateral tumor of the ovary occurring in women's reproductive age. Only about 10% of these patients are over 50 years of age. One third of these patients are suffering from signs of virilisation. This work summarizes the morphological and immunohistochemical characteristics of this tumor in a 56-year old woman with clinical signs of virilisation.

Androgens concentrations and second-to fourth-digit ratio (2D:4D) in girls with congenital adrenal hyperplasia (21-hydroxylase deficiency)

OBJECTIVES

Excessive hyperandrogenism, though proper hydrocortisone supplementation is a frequent clinical problem in girls with congenital adrenal hyperplasia (CAH). This may result from autonomic regulation of androgen production established in prenatal life. It has been suggested that the length of the second finger relative to the length of the fourth finger (2D;4D ratio) is negatively related to prenatal testosterone concentration.

DESIGN AND SETTING

The retrospective study aimed to establish the relationship between the level of androgenization in utero determined using 2D:4D ratio and serum androgen concentrations in treated girls with CAH (21-OH deficiency) has been performed on 19 girls with CAH (21-OH deficiency) at the age of 3.7-19 years (mean 13.8 ± 4.07 years). All subjects were adequately treated with hydrocortisone (10-19 mg/m2; mean 13.81 ± 4.07 mg/m2). Anthropometric measurements of digits length were performed in all girls on X-rays obtained for bone age estimation. Apart from it, serum androgens concentrations (testosterone, androstenedione, s-DHEA) and 17-OH-progesterone (17-OHP) were assayed.

RESULTS

Mean androgens serum concentrations in examined group were: testosterone 150.21 ± 155.44 ng/ml; androstenedione 4.15 ± 5.32 ng/ml, s-DHEA 70.39 ± 85.52 µg/dl. Mean 2D:4D ratio was 0.96 ± 0.04. Analysis of correlation showed positive linear correlations between testosterone, s-DHEA and 2D:4D ratio (r=0.53, p=0.023 and r=0.53; p=0.019, respectively).

CONCLUSIONS

2D:4D ratio parameter may be a simple test in indentification of female CAH patients prone to excessive androgen secretion despite proper treatment. The autonomization of adrenal androgens production in foetal life may cause its elevated levels in female patients with CAH although treated adequately.

Severe preeclampsia and fetal virilization in a spontaneous singleton pregnancy complicated by hyperreactio luteinalis

BACKGROUNDŕ: Hyperreactio luteinalis is a rare condition that stems from theca cell hyperplasia in the ovaries due to a high level of human chorionic gonadotropin during gestation. It occurs commonly in pregnant patients with trophoblastic disease, occasionally in multiple pregnancies, and rarely in normal singleton pregnancy.

CASE REPORT

A 24-year-old pregnant woman, G3 P0, who was admitted to the Perinatology Clinic with increasing findings of virilization during pregnancy was presented. The patient had bilaterally enlarged multicystic ovaries on sonographic examination and elevated serum androgen levels She was managed conservatively until 38th week of gestation as a presumptive diagnosis of hyperreactio luteinalis. Elevated blood pressure and prominent proteinuria were detected during the follow-up of the patient and labor was induced. She underwent an emergency caesarean delivery because of fetal distress. During caesarean section, ovarian biopsies were taken and a histopathological diagnosis of hyperreactio luteinalis was determined. The female fetus also presented virilization.

CONCLUSION

Although infrequent, hyperreactio luteinalis with both maternal and fetal virilization can occur in women with spontaneous singleton pregnancies. The clinical manifestations in such women may be complicated by severe preeclampsia.

Virilizing ovarian Krukenberg tumor in a 27-year-old pregnant woman. A case report and literature review

A case is reported of a 27-year-old pregnant woman with ovarian tumors, measuring 12 cm and 11.5 cm in the greatest diameter, discovered during investigation for virilization symptoms. Termination of the pregnancy at the 22nd week of gestation and tumorectomy with both adnexa were performed, with the provisional diagnosis of arrhenoblastoma. Pathological examination of the tumors showed typical Krukenberg neoplasms and subsequent upper GI tract endoscopy revealed a gastric cancer that was excised. The pathological examination revealed a diffuse type gastric adenocarcinoma with signet ring morphology, similar to ovarian tumors. In any case of ovarian tumor with unusual hormonal manifestations, in addition to hormonally active sex cord-stromal neoplasms, metastatic ovarian tumors must be considered as well, especially in cases of bilateral tumors.

Virilizing adrenocortical oncocytoma in a child: a case report

Functioning adrenocortical oncocytomas are extremely rare and most reported patients are 40-60 yr of age. To our knowledge, only 2 cases of functioning adrenocortical oncocytomas have been reported in childhood. We report a case of functioning adrenocortical oncocytoma in a 14-yr-old female child presenting with virilization. She presented with deepening of the voice and excessive hair growth, and elevation of plasma testosterone and dehydroepiandrosterone sulfate. She had an adrenalectomy. The completely resected tumor composed predominantly of oncocytes without atypical mitosis and necrosis. A discussion of this case and a review of the literature on this entity are presented.

No correlation between androgen receptor CAG and GGN repeat length and the degree of genital virilization in females with 21-hydroxylase deficiency

CONTEXT

In 21-hydroxylase (CYP21A2) deficiency (21OHD), the level of in vitro enzymatic function allows for classification of mutation groups (null, A, B, C) and prediction of disease severity. However, genital virilization in affected females correlates only weakly with CYP21A2 mutation groups, suggesting the influence of genetic modifiers.

OBJECTIVE

The objective of the study was to investigate the influence of the polymorphic CAG and GGn repeats of the androgen receptor (AR) gene on the degree of genital virilization in 21OHD females.

DESIGN AND PATIENTS

Design of the study was the determination of CYP21A2 genotype, degree of genital virilization (Prader stage), and X-weighted biallelic mean of AR CAG and GGn repeat length in 205 females with 21OHD.

OUTCOME MEASUREMENTS

Correlation of AR CAG and GGn repeat lengths with Prader stages using nested stepwise logistic regression analysis was measured.

RESULTS

CYP21A2 mutation groups null and A showed significantly higher levels of genital virilization than groups B and C (P < 0.01). However, Prader stages varied considerably within mutation groups: null, Prader I-V (median IV); A, Prader I-V (median IV); B, Prader I-V (median III); C, 0-III (median I). Mean GGn repeat length of patients was not significantly associated with Prader stages, classified as low (0-I), intermediate (II-III), or severe (IV-V) (odds ratio per repeat: 0.98, 95% confidence interval 0.71-1.35). In contrast, patients with Prader 0-I showed a trend toward longer CAG repeats without reaching statistical significance (P = 0.07, odds ratio per repeat: 0.82, 95% confidence interval 0.65-1.02).

CONCLUSION

Neither CAG nor GGn repeat lengths are statistically significant modifiers of genital virilization in females with 21OHD.

Lack of correlation between phenotype and genotype in untreated 21-hydroxylase-deficient Indonesian patients

BACKGROUND

Mutations in CYP21A2 lead to deficiency of 21-hydroxylase and can have either severe or moderate effects on phenotype, which can be prevented by early treatment. We studied long-term effects of this deficiency on phenotype in patients who had not been treated for prolonged periods and correlated these phenotypes with the mutations found in our patients.

OBJECTIVE

To assess the correlation between genotype and phenotype in untreated patients with 21-hydroxylase deficiency.

DESIGN

Subjects with 21-hydroxylase deficiency were selected from a large population of Indonesian patients with disorders of sexual differentiation. CYP21A2 mutations in these patients were correlated with their phenotype in terms of genital development and steroid hormone levels.

PATIENTS

Fifteen 46,XX patients with ages between 1 and 33 years, of whom 12 had never been treated before.

MEASUREMENTS

Mutations in CYP21A2, genital phenotype and steroid hormone levels.

RESULTS

We found in all patients CYP21A2 mutations which affect enzyme activity, with a relatively high allele frequency of R356W (40%), I172N (20%) and IVS2 - 1A > G (13%). Clitoris length was directly correlated with levels of testosterone, but not with age. The phenotype was not always concordant with the genotype: different phenotypes (mild to severe virilization) were found in sibling pairs with the mutations IVS2 - 13A > G or I172N. The high frequency of homozygous mutants for R356W in patients aged from 1 to 11 years old is remarkable, as this mutation has been described only in salt-wasting patients. In our study, this mutation caused a urogenital sinus in three out of seven cases, whereas in the remaining cases the labia were at least partially fused. This mutation caused severe virilization with remarkably high serum levels of renin. We found one novel substitution in intron 2 (IVS2 - 37A > G), containing the branch site, which is likely to affect the CYP21-enzyme. Two additional intron 2 substitutions were discovered, which are supposed to affect the 21-hydroxylase (i.e. IVS2 + 33A > C and IVS2 + 67C > T).

CONCLUSION

We conclude that a correlation exists between the concentration of androgens and the extent of virilization. However, there was no clear correlation between genotype and phenotype, except for the mutation R356W.

Phenotypic variability in 17beta-hydroxysteroid dehydrogenase-3 deficiency and diagnostic pitfalls

OBJECTIVE

17beta-hydroxysteroid dehydrogenase type 3 isoenzyme (17beta-HSD3) is required to produce testosterone for male sex differentiation. Mutations in the HSD17B3 gene cause 17betaHSD3 deficiency and result in XY sex reversal of varying degree. We report the phenotypes of 14 subjects with 17betaHSD3 deficiency in relation to sex of rearing, androgen production, and HSD17B3 mutations.

DESIGN

Cases were identified through the Cambridge Disorders of Sex Development Database where detailed clinical information was recorded, results of hCG stimulation tests were available, and HSD17B3 mutation was identified.

RESULTS

Fourteen subjects from seven pedigrees (four consanguineous) had the following seven mutations: A56T, N130S, E215D, S232L, C268Y, V205E, and a novel mutation M197K. XY sex reversal was classified as complete in 10 infants at birth. Inguinal masses suggestive of androgen insensitivity syndrome (AIS) occurred in five infants. Contrasexual virilization reminiscent of 5alpha-reductase deficiency occurred in four subjects at puberty. The median (range) testosterone : androstenedione (T/A) ratio after a short hCG stimulation test was 0.32 (0.12-3.4). The S232L mutation identified in three affected family members caused isolated, severe hypospadias in one member who was raised male; virilization occurred despite in vitro studies showing an inactive mutant enzyme. Ratios of T/A in this pedigree were more than 0.8.

CONCLUSION

XY sex reversal is sufficiently variable in 17betaHSD3 deficiency to cause problems in accurate diagnosis, particularly in distinguishing it from AIS. It should be considered in undervirilized male infants with normal Wolffian duct structures, absent Müllerian ducts, and normal adrenal steroid biosynthesis; or when an assigned female subject virilizes at puberty. Elevated hCG-stimulated T/A ratio may occur, and sex of rearing may not be concordant within affected families with the same HSD17B3 mutation. The T/A ratio, mutation analysis and functional analysis of the mutant enzyme taken in isolation, respectively, may not conclusively establish a diagnosis of 17betaHSD3 deficiency in undervirilized male subjects; the reasons for these discrepancies remain unknown.

An ovarian steroid cell tumor causing virilization and massive ascites

Steroid cell tumors, not otherwise specified (NOS), are rare ovarian sex cord-stromal tumors with malignant potential. The majority of these tumors produce several steroids, particularly testosterone. Various virilizing symptoms such as hirsutism, temporal balding, and amenorrhea are common in these patients; however massive ascites is an infrequent symptom. A 52-year-old woman with the sudden onset of virilization and massive ascites presented for treatment at Severance Hospital. After clinical evaluation, the patient underwent an exploratory laparotomy and a complete surgical staging procedure. She recovered from the surgery uneventfully and was discharged from the hospital five days after surgery. We present here an unusual case of an ovarian steroid cell tumor, NOS, and a brief review of the literature regarding these types of tumors.

Complex genital malformation in a female with congenital adrenal hyperplasia: evaluation with magnetic resonance imaging

This is a case of complex genital malformation in a young patient with congenital adrenal hyperplasia. The magnetic resonance imaging (MRI) findings included ostium of the vagina into the urethra (common urogenital opening), prostate-like tissue surrounding the urethra, and hyperplasia of the left adrenal gland. The report provides information on the clinical findings, the MRI examination, including the applied sequences and the MR findings, and gives an overview of the disease pattern and its frequency of occurrence.

Intraoperative venous blood sampling to localize a small androgen-producing ovarian tumor

BACKGROUND

Among other causes of virilization, ovarian tumors can be the cause of excessive androgen production. We report the case of a Leydig cell tumor of the ovary where diagnostic attempts to localize the source of hyperandrogenism preoperatively failed owing to relatively small tumor size.

CASE

A 36-year-old woman presented with clinical signs of severe virilization including progressive balding, increased hirsutism, secondary amenorrhea and enlargement of the clitoris. Extensive work-up included endocrinological tests, pelvic ultrasound, magnetic resonance imaging, chromosomal analysis, norcholesterol scintigraphy and selective venous sampling, without direct localization of the source of hyperandrogenism. Persistently high plasma testosterone prompted an explorative laparotomy. Intraoperative selective blood sampling of the ovarian veins and palpation gave evidence of a right ovarian tumor, which was then removed. Histological examination revealed the presence of a pure Leydig cell tumor.

CONCLUSION

Exploratory laparotomy with intraoperative selective blood sampling of the ovarian veins might be a useful approach in patients without accurate preoperative localization of androgen-producing tumors of the ovaries.

Neonatal androgenization affects the intrathymic T-cell maturation in rats

The thymus structure, expression of CD4/CD8/TCRalphabeta on thymocytes and thymocyte proliferative and apoptotic indexes were analyzed in sexually immature 30-day-old and in sexually mature 60-day-old female rats neonatally androgenized (NA) by subcutaneous injection of 500 microg testosterone propionate/day on days 1-3 and in their vehicle-administered counterparts. The treatment affected normal thymus development. Thus, at 30 days of age, there was a reduction in the thymus weight, reflecting a decrease in the main thymic compartments. However, at 60 days of age, thymus weight did not significantly differ from that in age-matched controls, since the cortical volume enlargement was followed by a proportional decrease in the medullary volume. In rats of both ages, the changes in thymic compartments most likely reflected alterations in the size of both lymphoid and nonlymphoid components. Furthermore, in NA rats, substantial changes in thymocyte phenotypic characteristics were registered, in spite of their age. In both groups of NA rats, a decrease in the relative proportion of the least mature CD4-8-TCRalphabeta- cells and in that of CD4+8- TCRalphabeta-/TCRalphabeta(low) cells followed by an increase in the percentage of their successor CD4+8+TCRalphabeta-/TCRalphabeta(low) cells was detected. In addition, in 30-day-old NA rats, the relative proportions of CD4+8+TCRalphabeta(high) cells (just positively selected) and that of mature single positive (CD4+8- and CD4-8+) and CD4-8- double negative TCRalphabeta(high) cells, were reduced, while in 60-day-old NA rats only the percentage of CD4+8+TCRalphabeta(high) thymocytes was decreased. Thus, the study showed that the changes in the development of the hypothalamo-pituitary-gonadal axis induced by neonatal androgenization may affect the thymus development and intrathymic T-cell maturation.

Virilisation in a case of transitional cell carcinoma of the ovary

A 52 year old woman presented with a five month history of emotional changes, voice changes, and of abdominal discomfort. Clinical, biochemical, and radiological examinations showed evidence of virilisation, raised testosterone, and a complex ovarian mass. Microscopy of the resection specimen showed the tumour to be a transitional cell carcinoma of the ovary with luteinisation and hyperplasia of the intervening stromal cells. This is a unique case of virilisation caused by transitional cell carcinoma of the ovary. Theories as to the origin of testosterone production in non-functioning ovarian tumours are discussed.

Agnogenic myeloid metaplasia in an ovarian steroid cell tumor with virilization: a case report

BACKGROUND

Extramedullary hematopoiesis in patients without hematologic disorders is very rare and has apparently never been described previously in association with an ovarian steroid cell tumor.

CASE

An 18-year-old woman was admitted to our clinic due to primary amenorrhea. the On examination she had significant facial hirsutism, clitoromegaly and and Adam's apple. The serum level of testosterone was elevated. A 7-cm, right ovarian mass was enucleated during laparotomy. Histology revealed a steroid cell tumor with foci of myeloid metaplasia; bony trabecula formation was present. There was no evidence of hematologic or systemic disease. The hormone values became normal 1 month postoperatively.

CONCLUSION

This report describes a patient with agnogenic myeloid metaplasia in an ovarian steroid cell tumor with virilization; this association was not previously reported.

Virilizing adrenocortical adenoma with Cushing's syndrome, thyroid papillary carcinoma and hypergastrinemia in a middle-aged woman

We report a rare case of virilizing adrenocortical adenoma complicated with Cushing's syndrome, thyroid papillary carcinoma and hypergastrinemia. A 45-year-old woman had a history of amenorrhea for 10 years, hypertension for 8 years, and diabetes mellitus for 3 years. Physical examination showed a masculinized woman with severe hirsutism, male-like baldness, deep voice, acne in the precordia, and clitorism. Plasma testosterone, DHEA-S and urinary 17-KS were high, and plasma cortisol level was it at the upper limit of the normal range, but it did not show a diurnal rhythm nor was suppressed by 2 and 8 mg of dexamethasone. Abdominal CT scan showed a left adrenal tumor (4.5 cm in size). Adrenal scintigram revealed uptake of the tracer on the left side, and plasma cortisol concentration was high in a blood sample from the left adrenal vein. Left adrenalectomy was performed. Histopathological features of resected adrenal tumor were consistent with those of adrenocortical adenoma, consisting of tumor cells with eosinophilic compact cytoplasm. Immunohistochemical staining for steroidogenic enzymes showed reactivity for P450sec, 3 beta-HSD, P450c17, P450c21 and P450c11. Plasma testosterone and cortisol levels decreased to the normal range postoperatively. The patient was also found to have a papillary thyroid carcinoma and hypergastrinemia. Our patient is a rare case of virilizing adrenocortical adenoma associated with Cushing's syndrome, thyroid papillary carcinoma, and hypergastrinemia.

The role of Müllerian inhibiting substance in the evaluation of phenotypic female patients with mild degrees of virilization

Müllerian inhibiting substance (MIS) is a sexually dimorphic gonadal hormone with proven efficacy in the evaluation of boys with cryptorchidism and children with intersex conditions. We examined the role of MIS determination in the evaluation of 65 phenotypic females with mild virilization. Among the 28 subjects with MIS values elevated above the normal female range, all had abnormal gonadal tissue: ovotestes in 11, testes in 7, dysgenetic gonads in 7, and MIS-secreting ovarian tumors in 3. Among the 37 children with serum MIS in the normal female range, 19 had detectable MIS and 18 had unmeasurable MIS. In the former group with measurable but normal female MIS values, 16 subjects had ovaries, 1 had an ovotestis, and 1 had dysgenetic gonads containing testicular elements. Of 18 children with undetectable MIS values, 16 had ovaries and 2 had ovarian dysgenesis. In this study, elevation of serum MIS above the normal female range was consistently associated with the presence of testicular tissue or MIS- secreting tumors, mandating additional evaluation and surgical exploration. A value within the normal female range in a virilized patient did not exclude dysgenetic testicular tissue or ovotestis, whereas undetectable values were consistent with the absence of testicular tissue.

Sexual differentiation of astrocyte morphology in the developing rat preoptic area

The preoptic area is an important brain region controlling sex-typic behaviour and physiology, and astrocytes of this region are responsive to steroids perinatally. Utilizing glial fibrillary acidic protein immunocytochemistry, the morphology of astrocytes in the preoptic area of male and female rat pups was examined on the day of birth and on postnatal day 3. As early as the day of birth, astrocytes of the male preoptic area exhibit both significantly greater primary process length and number of primary processes, and these differences remain at postnatal day 3. Application of exogenous steroid to females suggested that gonadal steroids, in particular oestradiol, mediate the sex difference. Pups received 100 micro g of steroid on the day of birth and again on postnatal day 1, and astrocyte morphology was assessed on postnatal day 3. Both oestradiol and testosterone induced significant changes in process length and number compared to vehicle-treated controls. Astrocytes of oestradiol-treated females did not differ on PN3 from those of PN3-untreated males. Exposure to the nonaromatizable steroid, dihydrotestosterone, had no effect on any attribute of astrocyte morphology. This suggests the effects induced by testosterone are mediated by oestradiol following local aromatization of the steroid, and not through direct activation of the androgen receptor. Astrocytes are important in synapse formation and efficacy, and we hypothesize a role for astrocyte complexity and differentiation in the establishment of synaptic patterning.

Age dependent changes in plasma anti-Müllerian hormone concentrations in the bovine male, female, and freemartin from birth to puberty: relationship between testosterone production and influence on sex differentiation

To understand the behaviour of the gonads, in terms of hormonal secretion, in a model of intersexual development naturally occurring in mammals, we determined plasma concentrations of testosterone, progesterone, and anti-Müllerian hormone (AMH) in bovine freemartins, and compared them to normal levels measured in males and females from birth to puberty. We found that newborn males and freemartins have very high concentrations of AMH (over 700ng/ml). Conversely, plasma AMH concentration is always below 120ng/ml in females. While values remain stable in males for the first five months of life, they sharply decrease in the freemartins within the first fortnight, and reach female levels, which demonstrates that AMH is essentially originated in the male twin. In young bulls the trend of plasma testosterone concentrations is opposite to that of the AMH. The rise in testosterone production at puberty corresponds to a sharp decline in AMH concentrations. Bovine plasma concentrations of AMH are surprisingly higher than those measured in other mammals, including man and mouse. The results obtained are discussed in reference to comparative aspects of endocrine functions.

Ovarian steroid cell tumor and a contralateral ovarian thecoma in a postmenopausal woman with severe hyperandrogenism

A 49-year-old woman presented with rapidly progressing hirsutism, receding hairline, male-pattern baldness and deepening of voice, which had developed over the past 2 years. Hormonal evaluation showed a markedly elevated serum testosterone level (418 ng/dl) and no evidence of increased production of cortisol, dehydroepiandrosterone, dehydroepiadrosterone-sulfate, androstenedione, or 17-hydroxyprogesterone. Transvaginal ultrasound examination suggested the presence of a small mass within the left ovary, but all other radiological studies, including adrenal and ovarian computed tomography, magnetic resonance imaging, radio-labelled cholesterol scintigraphy and positron emission tomography, were negative. Subsequently, bilateral selective venous sampling showed a marked testosterone gradient in the right ovarian vein. Bilateral salpingo-oophorectomy was performed (the patient had had a previous vaginal hysterectomy), and histopathological examination revealed a 10-mm steroid cell tumor within the right ovary and a 15-mm thecal cell tumor within the left ovary. The postoperative serum testosterone level returned to normal and the patient showed a slow regression of clinical symptoms. The simultaneous occurrence of a virilizing ovarian steroid cell tumor and an apparently non-functioning thecoma within the contralateral ovary emphasizes the potential pitfalls that may exist in the preoperative evaluation of patients with markedly increased testosterone production.

Development of imposex and accumulation of butyltin in the tropical muricid Thais distinguenda transplanted to a TBT contaminated site

The muricid Thais distinguenda (ca. 1,300 individuals) was collected from a pristine island in the Andaman Sea and tagged prior to translocation to an area of intense shipping activities. A minimum of 50 tagged individuals were recaptured 1, 2, 3, 5, 6, 7, 8 and 12 months after transplantation. The animals were separated into small (< or = 25 mm) and big (>25 mm) specimens based on total shell length and both incidence of imposex and body burden of butyltin (BT) were determined. After 3 months 16.7% of the small size and none of the big size class had developed imposex. After 5 months the incidence of imposex in the big and small size classes increased steadily with time reaching 86.4 and 80%, respectively after 1 year. Time after transplantation was significantly correlated with the incidence of imposex for the big size class (Spearman Rs=1; P=0.008); RPLI (Spearman Rs=1; P=0.008) and VDSI (Spearman Rs=1; P=0.008); and the small size class: incidence of imposex (Spearman Rs=1; P=0.006); RPLI (Spearman Rs=1; P=0.006) and VDSI (Spearman Rs=1: P=0.007). The development of imposex was not significantly related to body size after five months (chi square P<0.001). The body burden of tributyltin was not significantly different between the two size classes (paired t-test ) but the smaller animals had significantly higher concentrations of both dibutyltin (DBT; P<0.005) and monobutyltin (MBT; P<0.001). The use of transplantation experiments in addition to imposex surveys and analysis of body burden of tributyltin (TBT) can enhance the interpretation of the results and understanding of the time scale involved with the development of imposex.

Congenital adrenal hyperplasia: preliminary observations of the urethra in 9 cases

PURPOSE

Congenital adrenal hyperplasia is the most common cause of androgen mediated virilization of the genitourinary tract in females. In our study relative lengths of the internal genital duct structure were compared with the degree of virilization of the external genitalia.

MATERIALS AND METHODS

The records of 9 consecutive female patients with a median age of 2.6 years with congenital adrenal hyperplasia were studied. There were 4 normal females with a median age of 7.4 months who had a voiding cystourethrogram for urinary tract infection used as controls. The patients with congenital adrenal hyperplasia were stratified into groups as having mild, moderate or severe virilization based on preoperative photographs of external genitalia. By lateral voiding cystourethrograms the length of the proximal urethra, vagina and urogenital sinus was measured and standardized against the femoral metaphysis. The relative length of these internal genital structures was compared to the degree of virilization of the external genitalia.

RESULTS

There were 4 cases classified as normal, and 2 mildly, 4 moderately and 3 severely virilized. The urogenital sinus appeared to lengthen, with increasing virilization of the external genitalia. There was no trend for the proximal urethra to shorten with increasing virilization. The vagina also seemed to shorten with increasing virilization.

CONCLUSIONS

Our results suggest that the vagina enters the urogenital sinus at a fixed distance from the bladder neck. With increasing virilization, the majority of urethral lengthening occurs primarily distal to the vaginal opening, that is urogenital sinus lengthening.

[Androgenic alopecia revealing an androgen secreting ovarian tumor]

INTRODUCTION

Androgen-producing tumors of the ovary are rare in postmenopausal women and are revealed by severe virilization. Leydig hilus cell tumors are the most frequent postmenopausal virilizing tumors. In this report, an unusual and rare cause of alopecia due to Leydig cell hyperplasia within the wall of a simple cyst and in the ovarian hilus is described.

OBSERVATION

An 80 year-old woman complained of a 10-year history of severe androgenic alopecia associated with very mild facial hirsutism, without others signs of virilization. Hormonal blood levels showed markedly elevated testosterone. Computed tomographic scan of the adrenals and the ovaries revealed an enormous left ovarian cystic mass. Bilateral hystero-ophorectomy was performed. Histological examination demonstrated bilateral Leydig cell hyperplasia within the wall of the cyst and in the right ovarian hilus. Two months postoperative hormonal evaluation demonstrated dramatically decreased plasma levels of testosterone.

COMMENTARY

The clinical, X ray and histologic aspects of this case, although rare, show that the presence of virilization should lead to a search for an androgen-secreting ovarian or adrenal tumor.

Unexpected virilization in male mice lacking steroid 5 alpha-reductase enzymes

Mice lacking steroid 5 alpha-reductase 1 and 2 were produced by gene targeting and breeding. Male mice without 5 alpha-reductase 2 or without both enzymes had fully formed internal and external genitalia and were fertile, but had smaller prostates and seminal vesicles than controls. T accumulated to high levels in the reproductive tissues of the mutant mice. DHT administration increased seminal vesicle and coagulating gland weights in mice deficient in 5 alpha-reductase 2 and increased the weights of the prostate, seminal vesicle, and coagulating gland in animals deficient in both enzymes. An inhibitor of both 5 alpha-reductases (GI 208335X) decreased prostate and coagulating gland weights of control mice, but had no effect in those lacking 5 alpha-reductase 1 and 2. Castration reduced the sizes of these tissues in animals of all genotypes. Androgen-dependent gene expression was decreased in the seminal vesicles of mice lacking one or more 5 alpha-reductases and was restored by administration of T or DHT. Female mice missing both enzymes exhibited parturition and fecundity defects similar to those of animals without 5 alpha-reductase 1. We conclude that T is the only androgen required for differentiation of the male urogenital tract in mice and that the synthesis of DHT serves largely as a signal amplification mechanism.

Ovariectomy attenuates dendritic growth in hormone-sensitive spinal motoneurons

The lumbar spinal cord of rats contains the sexually dimorphic, steroid-sensitive spinal nucleus of the bulbocavernosus (SNB). Dendritic development of SNB motoneurons in male rats is biphasic, initially showing exuberant growth through 4 weeks of age followed by a retraction to mature lengths by 7 weeks of age. The initial growth is steroid dependent, attenuated by castration or aromatase inhibition, and supported by hormone replacement. Dendritic retraction is also steroid sensitive and can be prevented by testosterone treatment, but is unaffected by aromatase inhibition. Together, these results suggest a role for estrogens during the initial growth phase of SNB development. In this study, we tested whether ovarian hormones could support SNB somal and dendritic development. Motoneuron morphology was assessed in normal males and in females perinatally masculinized with dihydrotestosterone and then either ovariectomized or left intact. SNB motoneurons were retrogradely labeled with cholera toxin-HRP at 4 or 7 weeks of age and reconstructed in three dimensions. Initial growth of SNB dendrites was reduced after ovariectomy in masculinized females. However, no differences in dendritic length were seen at 7 weeks of age between intact and ovariectomized masculinized females, and lengths in both groups were significantly lower than those of normal males. Together with previous findings, these results suggest that estrogens are involved in the early growth of SNB dendrites, but not in their subsequent retraction.

Ovarian yolk sac tumor with virilization during pregnancy: immunohistochemical demonstration of Leydig cells as functioning stroma

A case is reported of yolk sac tumor occurring in the left ovary and complicated by pregnancy. The 22-year-old patient presented at 28 weeks gestation with virilization and elevated serum levels of testosterone and alpha-fetoprotein. The tumor showed the typical features of yolk sac tumor with a mixture of islands of Leydig cells. The accumulations of Leydig cells were well demarcated from the cellular components of the yolk sac tumor and were distributed throughout the tumor, although with predominant localization at the periphery. By immunohistochemistry the Leydig cells were intensely positive for vimentin and negative for cytokeratins, allowing clear distinction from the cell components of the yolk sac tumor, which were positive for cytokeratins and negative for vimentin. Testosterone was also identified in the cytoplasm of the Leydig cells. After tumor resection the testosterone and alpha-fetoprotein levels declined simultaneously; this, together with the immunohistochemical demonstration of testosterone, indicates that the Leydig cells were responsible for the endocrine manifestations. Furthermore, antibodies against inhibin alpha-subunit and calretinin could be used to detect the Leydig cells. The present case, a combination of yolk sac tumor and Leydig cells acting as a functioning stroma and causing virilization during pregnancy, is very rare.

Diffuse stromal Leydig cell hyperplasia: a unique cause of postmenopausal hyperandrogenism and virilization

A 60-year-old woman presented with diffuse scalp alopecia, hirsutism, and clitorimegaly, and the mean serum testosterone levels were greater than 200 ng/dL. Findings on computed tomography of both adrenal glands were normal. After bilateral oophorectomy, a unique histological picture consisting of diffuse stromal Leydig cell hyperplasia was found. Reinke crystals were present, but neither hilus cell hyperplasia nor stromal hyperthecosis was noted. Sequencing of the 11 exons of the gene for the luteinizing hormone receptor revealed no abnormality. Relevant data suggest that treatment of the postmenopausal woman with hyperandrogenism and virilization is bilateral laparoscopic oophorectomy if she has no pronounced ovarian enlargement or adrenal tumor on imaging. In this setting, an intensive endocrine evaluation or a search for metastatic disease seems to be unnecessary.

[A clinical study on virilization of external genitalia in congenital adrenal hyperplasia]

PURPOSE

In the newborn female with congenital adrenal hyperplasia (CAH), there are variable degrees of clitoral enlargement and virilization of the urethra. In order to investigate the factors that cause these variations, the degree of musculinization of the external genitalia in 44 patients with CAH was studied retrospectively.

PATIENTS AND METHODS

This study includes a total of 44 patients with CAH aged 2 months to 12 years and 11 months old who had consulted Nagoya City University Hospital from 1977 to 1994. The length of clitoris on the first consultation was compared with the age and its change was followed. Also, the relationship among the length of clitoris on the first consultation, the degree of urethral virilization, the clinical forms i.e. salt-losing or simple-virilization, and the glucocorticoid hormonal condition were investigated with each other. In 5 pairs of sisters, the length of clitoris on the first consultation was compared within each pairs, and also the degree of urethral virilization was compared.

RESULTS

The clitoral length on the first consultation was significantly correlated with the age (y = 1.8 x + 1.8, r = 0.7, p < 0.0001). The mean clitoral length at birth calculated from these data was 18 mm, which is as large as that of adult female one, and the clitoral enlargement rate was 1.8 mm/yr. The correlation was not clear between the clitoral length and the degree of urethral virilization, the clinical forms, and the glucocorticoid hormonal condition, either. On the other hand, the degree of urethral virilization was comparable within clitoral length was not comparable within them.

CONCLUSIONS

The urethral virilization was suggested to be determined by the internal hormonal environment during embryonal stage which was shared by the each pair of sisters. On the Other hand, the clitoral length was depend on the patient's age though the factor which determined the length was not apparent. These facts indicated that, not only the severely musculinizing cases, but also the new born female with mildly virilizing urethra should be followed strictly not to undergo the clitoral enlargement.

Virilizing mature ovarian cystic teratomas

Three further cases of mature benign cystic teratomas of the ovary associated with virilization are added to the three previously reported in the literature. They were found in postmenopausal, obese, diabetic women aged 52, 61, and 67 years. The patients presented with hirsutism and voice changes and clitoromegaly was present in one. Testosterone and androstenedione levels were elevated but promptly regressed after removal of the tumours. Histologically, sheets of stromal luteinized cells were found peripherally at the interface between the neoplasm and ovarian tissue. Luteinization of ovarian stroma induced by an unknown factor related to diabetes mellitus is the origin of the virilization.

Assessment of androgen receptor function in genital skin fibroblasts using a recombinant adenovirus to deliver an androgen-responsive reporter gene

Mutations of the androgen receptor (AR) cause defects in virilization and can result in a spectrum of phenotypic abnormalities of male sexual development that includes patients with a completely female phenotype (complete testicular feminization) and individuals with less severe defects of virilization, such as Reifenstein syndrome. These phenotypes are not specific for mutations of the AR gene, however, and defects in other genes can also result in similar abnormalities of male development. For this reason, the diagnosis of an AR defect is laborious and requires data from endocrine studies, the family history, and in vitro binding experiments. To assist in the evaluation of patients with possible AR defects, we previously employed the use of a recombinant adenovirus to deliver an androgen-responsive gene into fibroblast cultures to assay AR function in normal subjects and patients with complete forms of androgen resistance. Although these studies demonstrated measurable differences between these two groups of subjects, we did not assay samples from patients with partial defects of androgen action. In the current study, we have modified this method to examine AR function in three groups of patients with known or suspected defects of AR function: patients with Reifenstein syndrome, patients with spinobulbar muscular atrophy, and patients with severe forms of isolated hypospadias. When assayed using this method, the AR function of patients with Reifenstein syndrome was intermediate between that of normal control subjects and that of patients with complete testicular feminization. Using the parameters established by the aforementioned experiments, we found that defective AR function can be detected in fibroblasts established from patients with spinobulbar muscular atrophy and in some patients with severe forms of isolated hypospadias, including two with a normal AR gene sequence. These results suggest that this method may have some utility in screening samples to detect defects of AR function, particularly when viewed in the context of other AR assays results.

Pure Leydig cell tumour (hilus cell) of the ovary: a rare cause of virilization after menopause

A 58-year-old postmenopausal woman with high plasma testosterone levels and virilization, as demonstrated by hirsutism and alopecia, is presented. Urinary 17-ketosteroids and 17-hydroxycorticosteroids as well as the computed axial tomography scan of the adrenal glands were normal. Although no pelvic mass was detected by sonography or pelvic examination, the patient was found to have small pure Leydig cell tumour of the left ovary. Following total abdominal hysterectomy and bilateral salpingo-oophorectomy, the patient had regression of the hirsutism, and the plasma testosterone dropped to normal level.

An ovarian lipid cell tumour causing virilization and Cushing's syndrome

We report a 73-year-old woman with rapidly developing symptoms and signs of Cushing's syndrome and high urinary free cortisol. She was virilized and hirsute with testosterone levels which became exceptionally high. ACTH was suppressed and CT scan of the adrenals and pelvis showed no abnormality. Ultrasound scanning showed enlargement of the left ovary. Venous catheter studies suggested a left ovarian source. A 2-cm diameter lipid cell tumor was removed from the left ovary laparoscopically. Histology was initially benign, and clinical and biochemical cure of Cushing's syndrome was rapid. However, the neoplastic nature of the ovarian tumour was demonstrated 12 months later when peritoneal metastases were detected and there was then clinical and biochemical relapse.

Postmenopausal virilization due to ovarian hyperthecosis

A case of a 66-year-old obese woman with type II diabetes mellitus and a 4 year history of virilism is presented. After removal of the ovaries the raised testosterone levels returned to normal and signs of virilism gradually receded. The histological finding of nodular hyperthecosis of the ovaries is discussed in relation to hyperinsulinaemia.

Y chromosome mosaicism in the gonads, but not in the blood, of a girl with the Turner phenotype and virilized external genitalia

We describe a girl with virilized external genitalia and phenotypic features of Turner syndrome whose blood karyotype is 45,X. The presence of dysgenetic testicular tissue was confirmed by pathology. Using PCR and primers for the distal long arm, centromere and short arm of the Y chromosome, Y chromosome material was detected in her gonads but not in blood.

[Sertoli-Leydig-cell ovarian tumor with a retiform pattern and heterologous elements: a rare cause of virilization]

The case is presented of a young female with virilization signs and total circulating testosterone levels above 4 ng/ml, without a concomitant increase in cortisol, 17 OH-progesterone, DHEA-S, or androstenedion levels. On CT scan exam a tumoral mass in the left ovary was observed with polycystic characteristics similar to those observed in ovarian cystadenoma, inspite of the fact that most androgenic ovarian tumors are solid. The pathological study revealed an ovarian Sertoli-Leydig tumor associated to a reticular pattern with heterologous chondroid and mucinoid elements of cystadenoma.

[Postmenopausal virilization in thecosis of the ovaries]

We describe the case of a 74-year-old woman with a fifteen-year old history of virilism and with a Type-II-diabetes mellitus treated with insulin. After the removal of the ovaries, the formerly elevated serum-testosterone levels normalised and the signs of virilism gradually abated. The histological finding of stromal thecosis in the ovaries is discussed in relation to hyperinsulinaemia and other potential stimuli for ovarian stromal hyperplasia.

Early estrogen treatment of female zebra finches masculinizes the brain pathway for learned vocalizations

Telencephalic nucleus HVC and its two efferent targets, RA and X, play essential roles in the production of complex, learned vocalizations in the male zebra finch. Normal females do not produce these learned vocalizations; HVC, RA, and X are small in volume, and HVC and RA are not synaptically connected. We have shown that estrogen treatment during development causes females to learn and produce male-like vocalizations. This article describes the neural masculinization of these E2 females, replicating and extending the work of others. Female zebra finches were treated with 17 beta-estradiol (E2) at hatching, at 14-22 days of age, or as adults. In adulthood, the volumes of nucleus RA and area X were measured and the efferent projections of nucleus HVC examined using the anterograde tracer PHA-L. Early, sustained E2 treatment caused the greatest increase in the volume of RA and X, the innervation of RA and X by HVC axons, and the masculinization of auditory responses of cells in RA. Treatments that lasted for a shorter period or started later in development resulted in different patterns of partial brain masculinization. E2 treatment in adulthood had no effect on the volume of RA or X or their innervation by HVC. Bilateral lesions of the tracheosyringeal nerves or of HVC had the same effects on the male-typical vocalizations produced by E2 females as they do on the vocalizations produced by males. These results demonstrate that the neural masculinization of telencephalic nuclei induced by E2 treatment sets up a functional circuit in females similar to one in males that enables the learning and production of complex vocalizations.