An Inhibin B and Estrogen-Secreting Adrenocortical Carcinoma Leading to Selective FSH Suppression

Reversal of a Blunted Follicle-Stimulating Hormone by Chemotherapy in an Inhibin B-Secreting Adrenocortical Carcinoma

Context

Adrenocortical carcinomas (ACCs) are revealed in 60% of cases by steroid hypersecretion. Alternatively, it is uncommon to observe a paraneoplastic syndrome due to a peptide oversecretion.

Case Description

We describe a 60-year-old man with a right adrenal mass. Hormonal evaluation showed an ACTH-independent Cushing syndrome. Surprisingly, follicle-stimulating hormone (FSH) levels were suppressed and blunted during gonadotropin-releasing hormone stimulation, despite normal luteinizing hormone levels. Levels of inhibin B, which negatively regulates the pituitary FSH, were very high. Given the atypical hormonal findings, an adrenal mass biopsy was performed, which allowed the diagnosis of an adrenocortical tumor (positive for steroidogenic factor-1 immunostaining). Moreover, an intense α-inhibin subunit immunostaining was observed. Because of the presence of metastases, the patient received mitotane and chemotherapy (etoposide and cisplatin). After 2 cycles, the inhibin B dropped. After 5 cycles, tumor size was reduced by 15%. Inhibin B levels remained low, and basal and gonadotropin-releasing hormone-stimulated FSH levels normalized. The patient underwent tumor resection, and pathology confirmed the ACC diagnosis (Weiss score of 9). The intensity of the α-inhibin subunit immunostaining was significantly decreased.

Conclusions

We report the case of an inhibin B-secreting ACC in which the response to chemotherapy and mitotane was associated with a normalization of inhibin B secretion, allowing the reversal of the blunted FSH secretion. Inhibin B should be measured in case of suppressed FSH levels despite normal luteinizing hormone levels and may be considered a tumoral marker in some ACCs, even during treatment follow-up.

Gonadectomy-related adrenocortical tumors in ferrets demonstrate increased expression of androgen and estrogen synthesizing enzymes together with high inhibin expression

The 2 objectives of this study were to (1) measure by quantitative polymerase chain reaction the expression of genes involved in steroid and inhibin synthesis in adrenocortical tumors of gonadectomized ferrets and (2) localize by immunohistochemistry several proteins that are key to adrenal steroidogenesis. Relative to the control adrenals, expression of the messenger RNAs encoding StAR (steroidogenic acute regulatory protein; P = 0.039), CYP11A (P = 0.019), CYP21 (P = 0.01), and 3β-HSD (P = 0.004), all involved in the synthesis of mineralocorticoids and glucocorticoids, were decreased in the adrenocortical tumors. In contrast, expression of cytochrome B5 (CytB5; P = 0.0001) and aromatase (P = 0.003), involved in androgen and estrogen synthesis, and both inhibin α-subunit (P = 0.002) and βB-subunit (P = 0.001) were upregulated. In tumors, immunostaining of CYP21 was low, whereas staining of Cyp17 and CytB5, necessary for androgen synthesis, was present. It is concluded that ferret adrenocortical tumors express genes for androgen production. In addition, the expression of aromatase and inhibin suggests an even more gonadal differentiation, which is reminiscent to the fact that both gonads and adrenals are derived from a common urogenital primordial cell.

Autocrine/paracrine regulatory mechanisms in adrenocortical neoplasms responsible for primary adrenal hypercorticism

A wide variety of autocrine/paracrine bioactive signals are able to modulate corticosteroid secretion in the human adrenal gland. These regulatory factors, released in the vicinity of adrenocortical cells by diverse cell types comprising chromaffin cells, nerve terminals, cells of the immune system, endothelial cells, and adipocytes, include neuropeptides, biogenic amines, and cytokines. A growing body of evidence now suggests that paracrine mechanisms may also play an important role in the physiopathology of adrenocortical hyperplasias and tumors responsible for primary adrenal steroid excess. These intra-adrenal regulatory systems, although globally involving the same actors as those observed in the normal gland, display alterations at different levels, which reinforce the capacity of paracrine factors to stimulate the activity of adrenocortical cells. The main modifications in the adrenal local control systems reported by now include hyperplasia of cells producing the paracrine factors and abnormal expression of the latter and their receptors. Because steroid-secreting adrenal neoplasms are independent of the classical endocrine regulatory factors angiotensin II and ACTH, which are respectively suppressed by hyperaldosteronism and hypercortisolism, these lesions have long been considered as autonomous tissues. However, the presence of stimulatory substances within the neoplastic tissues suggests that steroid hypersecretion is driven by autocrine/paracrine loops that should be regarded as promising targets for pharmacological treatments of primary adrenal disorders. This new potential therapeutic approach may constitute an alternative to surgical removal of the lesions that is classically recommended in order to cure steroid excess.

Feminizing adrenal tumors: Our experience about three cases

Feminizing adrenal tumors (FATs) are very rare as they account for less than 2% of all the adrenal neoplasms. Their prognosis is deemed to be very poor. We aimed to present a mono centre (adult and pediatric) experience over a long period of time (January 1980 to Jun 2012). During the study period, we observed only three cases in men aged 22 (2 cases) and 45 (1 case). They all consulted for a painful gynecomastia, decreased libido and impotency. Estradiol was high in two cases at presentation, and after a relapsing tumor in the third one. All had big adrenal tumors (5.9, 6, and 17 cm), and a mixed secretion composed by high estradiol and cortisol. The pathological study argued for malignancy in two cases. But, only one had diffuse metastasis and died 4 years after diagnosis; the others diagnosed one and three years ago are still alive without any metastasis or relapsing.

Inhibins and activins: their roles in the adrenal gland and the development of adrenocortical tumors

The adrenal gland is composed of two separate endocrine tissues that control a multitude of bodily functions in their adaptation to external and internal stressors through hormone secretion. The functions of the adrenal gland are regulated by circulating, neural and local factors that ensure proper cell growth and hormone production. Activins and inhibins are among the locally expressed growth factors affecting adrenal cell function. They have been found to influence several aspects of adrenal cell development, adrenocortical steroidogenesis, adrenocortical tumor formation and adrenomedullary cell differentiation. Especially the finding that inhibin α-subunit knockout mice develop adrenocortical carcinomas after gonadectomy has prompted research on the physiological and pathophysiological roles of activin and inhibin in the adrenal cortex. It is now clear that both peptides control adrenocortical physiology and are involved in adrenocortical tumorigenesis at multiple levels, both in murine models as well as in human patients.

Serum inhibin pro-αC is a tumor marker for adrenocortical carcinomas

OBJECTIVE

The insufficient diagnostic accuracy for differentiation between benign and malignant adrenocortical disease and lack of sensitive markers reflecting tumor load emphasize the need for novel biomarkers for diagnosis and follow-up of adrenocortical carcinoma (ACC).

DESIGN

Since the inhibin α-subunit is expressed within the adrenal cortex, the role of serum inhibin pro-αC as a tumor marker for ACC was studied in patients.

METHODS

Regulation of adrenal pro-αC secretion was investigated by adrenocortical function tests. Serum inhibin pro-αC levels were measured in controls (n=181) and patients with adrenocortical hyperplasia (n=45), adrenocortical adenoma (ADA, n=32), ACC (n=32), or non-cortical tumors (n=12). Steroid hormone, ACTH, and inhibin A and B levels were also estimated in patient subsets.

RESULTS

Serum inhibin pro-αC levels increased by 16% after stimulation with ACTH (P=0.043). ACC patients had higher serum inhibin pro-αC levels than controls (medians 733 vs 307 ng/l, P<0.0001) and patients with adrenocortical hyperplasia, ADA, or non-adrenocortical adrenal tumors (148, 208, and 131 ng/l, respectively, P=0.0003). Inhibin pro-αC measurement in ACC patients had a sensitivity of 59% and specificity of 84% for differentiation from ADA patients. Receiver operating characteristic analysis displayed areas under the curve of 0.87 for ACC vs controls and 0.81 for ACC vs ADA (P<0.0001). Surgery or mitotane therapy was followed by a decrease of inhibin pro-αC levels in 10/10 ACC patients tested during follow-up (P=0.0065).

CONCLUSIONS

Inhibin pro-αC is produced by the adrenal gland. Differentiation between ADA and ACC by serum inhibin pro-αC is limited, but its levels may constitute a novel tumor marker for ACC.

Feminizing adrenocortical carcinoma with selective suppression of follicle-stimulating hormone secretion and disorganized steroidogenesis: a case report and literature review

We report a 61-year-old male with gynecomastia, poor libido and erectile dysfunction. Endocrinological studies showed high levels of estradiol and dehydroepiandrosterone sulfate. Although luteinizing hormone (LH) level was within the normal limit, the concentration of follicle-stimulating hormone (FSH) was under the normal limit. Delayed response of LH and poor response of FSH to gonadotropin-releasing hormone administration were detected. Magnetic resonance imaging of the abdomen revealed a left adrenal tumor. Although the surgically-resected tumor was diagnosed as a high grade ACC based on Weiss's criteria of adrenocortical malignancy, no metastasis was detected. Since estrogen levels normalized after resection, feminizing ACC was confirmed. While LH concentration increased slightly after operation, FSH level became transiently elevated over the normal limit, and finally reached the normal range. These data may suggest that FSH was suppressed selectively by hormone produced by ACC different from estrogen.