Virilizing oncocytic adrenocortical carcinoma: clinical and immunohistochemical studies

CONTEXT

Oncocytic tumors of the adrenal cortex are rare, mostly nonfunctioning and benign.

SETTING

Report virilizing oncocytic adrenocortical carcinoma in a 50-year-old woman.

PATIENT

She presented a recent and progressive virilization syndrome, associated with high blood pressure. Hormonal evaluation showed elevated serum testosterone and delta-4-androstenedione levels, normal urinary free cortisol level and incomplete suppression of cortisol at the 1 mg dexamethasone suppression test. CT scan of the abdomen revealed a 35 mm left adrenal mass.

INTERVENTION

The patient underwent a left adrenalectomy, and the histological study showed a 3 cm oncocytic adrenocortical carcinoma with signs of malignancy.

RESULTS

Immunohistochemical study revealed that tumor cells expressed the steroidogenic enzymes involved into androgen synthesis (3βHSD and P450c17α), P450 aromatase and luteinizing hormone (LH) receptors. Post-operatively, signs of virilization improved rapidly, serum testosterone and delta-4-androstenedione levels returned to normal, as did the dexamethasone suppression test. During follow-up CT-scan and 18-FDG PET/CT showed a right ovary mass, corresponding to a follicular cyst associated with hyperthecosis. The patient is alive with no recurrence 48 months after adrenal surgery.

CONCLUSION

Oncocytic adrenocortical carcinomas, although extremely rare, should be considered in women with a virilization syndrome. In this woman immunohistochimical studies revealed the presence of steroidogenic enzymes involved into androgen synthesis and aromatization, and LH receptors could be implicated in this pathology.

Characterization of a novel CYP19A1 (aromatase) R192H mutation causing virilization of a 46,XX newborn, undervirilization of the 46,XY brother, but no virilization of the mother during pregnancies

BACKGROUND

P450 aromatase (CYP19A1) is essential for the biosynthesis of estrogens from androgen precursors. Mutations in the coding region of CYP19A1 lead to autosomal recessive aromatase deficiency. To date over 20 subjects have been reported with aromatase deficiency which may manifest during fetal life with maternal virilization and virilization of the external genitalia of a female fetus due to low aromatase activity in the steroid metabolizing fetal-placental unit and thus high androgen levels. During infancy, girls often have ovarian cysts and thereafter fail to enter puberty showing signs of variable degree of androgen excess. Moreover, impact on growth, skeletal maturation and other metabolic parameters is seen in both sexes.

OBJECTIVE AND HYPOTHESIS

We found a novel homozygous CYP19A1 mutation in a 46,XX girl who was born at term to consanguineous parents. Although the mother did not virilize during pregnancy, the baby was found to have a complex genital anomaly at birth (enlarged genital tubercle, fusion of labioscrotal folds) with elevated androgens at birth, normalizing thereafter. Presence of 46,XX karyotype and female internal genital organs (uterus, vagina) together with biochemical findings and follow-up showing regression of clitoral hypertrophy, as well as elevated FSH suggested aromatase deficiency. Interestingly, her older brother presented with mild hypospadias and bilateral cryptorchidism and was found to carry the same homozygous CYP19A1 mutation. To confirm the clinical diagnosis, genetic, functional and computational studies were performed.

METHODS AND RESULTS

Genetic analysis revealed a homozygous R192H mutation in the CYP19A1 gene. This novel mutation was characterized for its enzymatic activity (Km, Vmax) in a cell model and found to have markedly reduced catalytic activity when compared to wild-type aromatase; thus explaining the phenotype. Computational studies suggest that R192H disrupts the substrate access channel in CYP19A1 that may affect binding of substrates and exit of catalytic products.

CONCLUSION

R192H is a novel CYP19A1 mutation which causes a severe phenotype of aromatase deficiency in a 46,XX newborn and maybe hypospadias and cryptorchidism in a 46,XY, but no maternal androgen excess during pregnancy.

Recognition of 5α-reductase-2 deficiency in an adult female 46XY DSD clinic

CONTEXT

The late presentation of steroid 5α-reductase-2 (SRD5A2) deficiency in females is poorly characterised. The ratios of 5α/5β-reduced metabolites of adrenal steroids in a urine steroid profile (USP) can give an indication of SRD5A2 deficiency, although the diagnostic cut-off for 5α/5β ratios are not clearly defined in genetically confirmed cases.

OBJECTIVE

The aim of this study was to establish the frequency of SRD5A2 deficiency in an adult clinic for disorders of sexual development (DSD) focussing on 46XY partially virilised adult female subjects. We investigated the relationship between USP results and SRD5A2 genetic sequence and determined the cut-off for USP 5α/5β-reduced steroid ratios compared with gene sequencing for the identification of SRD5A2 deficiency.

METHODS

USP and SRD5A2 genetic analyses were performed in 23 adult females, aged 19-57 years, with 46XY DSD and in four males with confirmed SRD5A2 deficiency. 5α-Reductase activity was assessed using the USP ratio of androsterone to aetiocholanolone (A/Ae), 5α-tetrahydrocortisol (5α-THF)/tetrahydrocortisol (THF) and 5α-tetrahydrocorticosterone to tetrahydrocorticosterone (5α-THB/THB).

RESULTS

The SRD5A2 gene mutations were found in 10/23 (43%) females and in all four males. Totally, four novel mutations were identified. All mutation-positive subjects had A/Ae and 5α-THB/THB ratios below the lower limit of normal (100% sensitivity) while the sensitivity of 5α-THF/THF ratio was 90%.

CONCLUSION

SRD5A2 deficiency is more prevalent than expected in the adult female 46XY DSD population. The clinical spectrum of this disorder may extend to a more female phenotype than previously considered to include individuals with little or no virilisation.

Human HSD17B1 expression masculinizes transgenic female mice

When present in excess amounts during fetal life, androgens can impair female development by inducing masculinization. On way to modify fetal steroid concentration is by altering the expression of hydroxysteroid (17beta) dehydrogenases (HSD17Bs). Human HSD17B1 converts weak estrogen estrone to estradiol, and with lower catalytic efficiency, weak androgen androstenedione to testosterone. We have recently shown that over-expression of human HSD17B1 in transgenic mice results in masculinized phenotype in female mice. In the present study, we further show that in addition to the Müllerian ducts, HSD17B1TG females have internal structures resembling Wolffian ducts, and enlarged Skene paraurethral gland, also called the female prostate. HSD17B1 expression has been found in fetal human ovary, thus, it is possible that HSD17B1 contributes to maintain the normal steroid hormone concentration during development. Thereby, abnormal increase in the fetal expression of HSD17B1 could contribute to the development of hormonal imbalances, and so result in female masculinization.

Placental Expression and Molecular Characterization of Aromatase Cytochrome P450 in the Spotted Hyena (Crocuta crocuta)

At birth, the external genitalia of female spotted hyenas (Crocuta crocuta) are the most masculinized of any known mammal, but are still sexually differentiated. Placental aromatase cytochrome P450 (P450arom) is an important route of androgen metabolism protecting human female fetuses from virilization in utero. Therefore, placental P450arom expression was examined in spotted hyenas to determine levels during genital differentiation, and to compare molecular characteristics between the hyena and human placental enzymes. Hyena placental P450arom activity was determined at gestational days (GD) 31, 35, 45, 65 and 95 (term, 110), and the relative sensitivity of hyena and human placental enzyme to inhibition by the specific inhibitor, Letrozole, was also examined. Expression of hyena P450arom in placenta was localized by immuno-histochemistry, and a full-length cDNA was cloned for phylogenetic analysis. Aromatase activity increased from GD31 to a peak at 45 and 65, apparently decreasing later in gestation. This activity was more sensitive to inhibition by Letrozole than was human placental aromatase activity. Expression of P450arom was localized to syncytiotrophoblast and giant cells of mid-gestation placentas. The coding sequence of hyena P450arom was 94% and 86% identical to the canine and human enzymes respectively, as reflected by phylogenetic analyses. These data demonstrate for the first time that hyena placental aromatase activity is comparable to that of human placentas when genital differentiation is in progress. This suggests that even in female spotted hyenas clitoral differentiation is likely protected from virilization by placental androgen metabolism. Decreased placental aromatase activity in late gestation may be equally important in allowing androgen to program behaviors at birth. Although hyena P450arom is closely related to the canine enzyme, both placental anatomy and P450arom expression differ. Other hyaenids and carnivores must be investigated to determine the morphological and functional ancestral state of their placentas, as it relates to evolutionary relationships among species in this important taxonomic group.

Congenital adrenal hyperplasia in the Bahamas due to 21-hydroxylase deficiency

OBJECTIVE

To determine the frequency of 21-hydroxylase deficiency in The Bahamas and the spectrum of this disorder

METHODS

Patients referred for evaluation of virilization, precocious puberty, ambiguous genitalia and salt wasting had blood taken for 17-hydroxyprogesterone (17-OH progesterone) which was measured by Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS

Nine patients had elevated 17-OH progesterone levels--confirming 21-hydroxylase deficiency. Range of levels was 174.9 nmol/l to 81678.7 nmol/L (normal less than 13 nmol/L). There were six females and three males and the age at diagnosis ranged from 21 days to 16 years. Five had precocious development, three had salt wasting, and there was one with virilization. One of the salt wasters had ambiguous genitalia. Incidence of 2l-hydroxylase deficiency--20/100,000; salt wasting--35/100,000; the prevalence of 21-Hydroxylase deficiency 10/100,000).

CONCLUSION

The frequency of 21-Hydroxylase deficiency in The Bahamas is one of the highest worldwide.

Profile of children with congenital adrenal hyperplasia--a hospital study

OBJECTIVE

To collect baseline information on congenital adrenal hyperplasia (CAH) and to identify relevant issues specific to this disease in Pakistan.

METHODS

A retrospective analysis of medical records of pediatric patients registered for serum 17 hydroxyprogesterone (17-OHP) measurement and documented to have CAH in the period 1987 to 1998 was carried out at The Aga Khan University, Karachi (AKU). The clinical notes were reviewed for documentation of CAH as the diagnosis.

RESULTS

Of the 152 children registered for 17-OHP testing, sixty-three were diagnosed with CAH. Salt wasting, simple virilization and non-classical CAH was found in 40 (63%), 18 (29.0%) and 5 (8.0%) patients respectively. Twenty-one (33.9%) patients were incorrectly assigned sex and of these, 20 (32.2%) patients were females who were either considered males or just not assigned gender. Parental consanguinity was found in 33 (52.3%) cases. No case had a history of similar features in either parent but in 19 (30.6%) cases similar features were present in siblings. Sixteen cases (25.4%) had a history of sibling death in the neonatal period and 7 had a history of sibling death in infancy. Maternal obstetric histories identified 3 (4.8%) cases with a history of still birth(s) and 4 (6.4%) with a history of abortion(s).

CONCLUSION

Children with CAH should be diagnosed early as a rational and judicious choice of sex assignment is a critical aspect of treatment. The high rate of consanguinity emphasized the need to establish the true incidence of the defect in Pakistani population.

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.

CYP21 mutations in simple virilizing congenital adrenal hyperplasia

We studied the functional and structural effects of two unique missense mutations in CYP21 found in patients with simple virilizing congenital adrenal hyperplasia. The rare variants L300F and V281G were found in two girls who were each hemizygous for one of the mutations. Functional analysis after expression in COS-1 cells revealed that the mutant enzymes had reduced enzymatic activity for conversion of both 17-hydroxyprogesterone (L300F 9.5%, V281G 3.9% of normal) and progesterone (L300F 4.4%, V281G 3.9% of normal). Both mutant enzymes had an increased degradation in mammalian COS-1 cells compared to the normal protein, although the L300F variant affected the degradation pattern to a greater extent. Our data indicate that the residue L300 is important in maintaining normal structure of the 21-hydroxylase enzyme whereas mutations affecting V281 most likely cause impaired enzyme activity by interfering with a specific function(s) of the protein.

Progressive virilization of a pubertal phenotypic female: 17 beta-hydroxysteroid dehydrogenase deficiency

17 beta-Hydroxysteroid dehydrogenase deficiency is an uncommon inherited disorder characterized by genital ambiguity and progressive pubertal virilization. We describe the clinical and biochemical features in a 13-year-old 46, XY individual who presented with progressive pubertal virilization.

A de novo pathological point mutation at the 21-hydroxylase locus: implications for gene conversion in the human genome

More than two hundred characterized 21-hydroxylase deficiency alleles appear to result exclusively from sequence exchanges involving the 21-hydroxylase gene (CYP21B) and a closely related pseudogene (CYP21A). Gene conversion-like events have also been reported in many other human gene clusters, but in the absence of a de novo mutation, the alternative explanation of a multiple recombination is possible. We now report a de novo pathological mutation at the 21-hydroxylase locus. DNA sequence analysis suggests that the mutation arose by a microconversion event involving exchange of up to 390 nucleotides between maternal CYP21A and CYP21B genes. This putative de novo gene conversion event appears to be the first characterized in humans.

Late-onset 3 beta-hydroxysteroid dehydrogenase deficiency with virilization induced by a large ovarian cyst

A midpubertal girl presented with secondary amenorrhea and a rapidly progressive deepening of her voice as the only signs of virilization. Diagnostic work-up yielded an extremely elevated plasma testosterone (289 ng/dl), low estradiol (29 pg/ml) levels and a large solitary cyst of the right ovary, which was totally removed. Pathohistology was in keeping with a granulosa cyst with mild luteinization. Normalization of testosterone (to 27.3 ng/dl) and estradiol (to 62 pg/ml) and resumption of regular menses after 2 months clearly indicated an autonomous function of the cyst. A malignant tumor was unequivocally excluded. Basal and ACTH stimulated levels of adrenal androgens pointed to a late-onset 3 beta-hydroxysteroid dehydrogenase deficiency, which per se is known to induce polycystic ovarian changes, but to date has never been described to be accompanied with a large and autonomous follicular cyst.

Virilization without adrenal hyperplasia in 21-hydroxylase deficiency during fetal life

The characteristic excess production of androgens in the cortisol 21-hydroxylase defect is generally considered to be secondary to ACTH stimulation of alternate pathways. Whenever a morphological examination of the adrenals has been possible in this disorder, adrenocortical hyperplasia was a constant finding. The availability of methods for the prenatal diagnosis of the 21-hydroxylase defect has made it possible to examine some of the manifestations of this disorder during fetal life. We studied a severely virilized 20-week-old aborted female fetus with the 21-hydroxylase defect whose adrenals were neither grossly enlarged nor microscopically hyperplastic. In a pregnancy at risk for congenital adrenal hyperplasia due to a 21-hydroxylase deficiency, amniocentesis was performed in the 18th week of gestation. The 21-hydroxylase defect was established by HLA typing and highly elevated levels of 17-hydroxyprogesterone, testosterone, and androstendione in amniotic fluid. After counselling, the parents, who already had a girl with the salt-wasting form of 21-hydroxylase deficiency, wished termination of the pregnancy. The aborted 20-week-old fetus was within the normal range for gestational age in weight and height. The external genitalia were ambiguous and extremely virilized, with an enlarged clitoris and fused labioscrotal folds. A urogenital sinus opened at the base of the clitoris. The internal organs were female, with a normal uterus and ovaries. Both adrenals were normal in size and weight for their gestational age. Histological examination of the adrenals revealed no abnormalities, and no hyperplasia was detectable. Thus, the adrenals in the 21-hydroxylase defect during fetal life secrete excessive amounts of androgens and cause virilization in the absence of adrenocortical hyperplasia.

Increased 17 beta-hydroxysteroid dehydrogenase activity in a masculinizing adrenal adenoma in a patient with isolated testosterone overproduction

The patient studied had noted the onset of virilization shortly after menopause. Urinary 17-ketosteroid levels were normal, as were fractionated 17-ketosteroid levels by gas liquid chromatography, but for 3 yr, serum testosterone levels had been greater than 490 ng/dl. The ovaries were found to be normal by laparoscopy. Abdominal exploration revealed a 1-cm adenoma in the right adrenal. A part of the adenoma excised from our patient was homogenized and incubated with 5 microCi [14C]androstenedione. Five percent of the 14C was converted by the tumor homogenate to a metabolite with the same mobility as testosterone on LH-20 chromatography. After thin layer chromatography, the radiolabeled material together with 3H-labeled authentic testosterone were crystallized to a constant specific activity. The net rate of testosterone synthesis by the tumor was 26 pmol/mg wet tissue wt.h vs. 0.56 pmol/mg.h by a control adrenal homogenate. Thus, the tumor demonstrated a 50-fold increase in 17 beta-hydroxysteroid dehydrogenase activity compared to normal adrenal tissue. This is the first report to identify altered activity of a specific enzyme system in this syndrome of isolated adrenal testosterone overproduction.

Enzyme histochemistry of ovarina lipoid cell hyperplasia in a masculinized patient

In an effort to better identify the specific steroids produced by histologically similar cells of certain ovarian tumors, a battery of histochemical assays was performed on a masculinizing tumor removed from a 21-year-old patient. Certain reactions were distinguished that seemed to be specific for the histologically classic luteinized stromal cell, and these reactions can be correlated with those obtained with Leydig and hilar cells. The apparent precursors of the interstitial cells (ISC) of this tumor, and to a lesser extent the immature ISC, possess unusually high cholinesterase activity, especially with the butyryl ester. The importance of the perivascular and neural elements in the process of steroidogenesis is suggested by the findings in this case.

Defective steroidal synthesis by adrenal tissue: the control of gene expression causing loss of active steroidogenic enzymes

RNA was isolated from normal human adrenal glands and found to cause the formation of Δ5-3β-hydroxysteroid dehydrogenase-isomerase and steroid 21-hydroxylase activities by a Krebs II ascites cell-free protein synthesising system. Although no functional steroid 21-hydroxylase in vivo or in vitro was found in a gland from a patient with virilism due to congenital adrenocortical hyperplasia the RNA would still give steroid 21-hydroxylase-like activity in the protein synthesising system which suggests that the inherited defect was not in the structural gene. Activity could not be induced by RNA from a 'non-functioning' adrenocortical tumour or rat liver.