Co-occurrence of Functional Gonadotroph Adenoma and Lactotroph Adenoma: A Case Report and Literature Review

Background/Objective

Functional gonadotroph adenomas (FGAs) are adenomas producing active gonadotropins, follicle-stimulating hormone or luteinizing hormone. Double pituitary adenomas are 2 distinct adenomas occurring in an individual. This report aimed to present an extremely rare case of an FGA, itself an uncommon disorder, co-occurring with a lactotroph adenoma.

Case Report

A 33-year-old woman presented with menorrhagia and was found to have ovarian enlargement, large uterine leiomyomas, and bitemporal hemianopsia. Initially, the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, and prolactin were 73.3 mIU/mL (midcycle peak, 2.3-20.9 mIU/L), 3.74 mIU/L (midcycle peak, 8.7-76.3 mIU/L), 1071 pg/mL (midcycle peak 38-649 pg/mL), and 402 ng/mL (2-30 ng/mL), respectively. Pituitary magnetic resonance imaging demonstrated a single sellar mass (2.0 × 2.2 cm). Two months of cabergoline did not reverse visual field deficits; therefore, transsphenoidal resection was performed. Diagnosis of 2 separate adenomas, a gonadotroph and lactotroph adenoma, was confirmed on pathology.

Discussion

In this case, gonadotropins did not suppress in response to hyperprolactinemia. Although marked hyperprolactinemia has been associated with functional and clinically silent gonadotroph adenomas in prior cases, this is the first case to confirm an FGA co-occurring with a lactotroph adenoma.

Conclusion

In patients who present with elevated gonadotropin levels despite hyperprolactinemia, we suggest considering FGA. Further research is needed to clarify whether there is underdiagnosis of lactotroph adenomas co-occurring with gonadotroph adenomas.

Cabergoline as an adjuvant to standard heart failure treatment in peripartum cardiomyopathy: A case report and review of the literature

Introduction

Peripartum cardiomyopathy (PPCM) is a rare and idiopathic form of dilated cardiomyopathy presenting late in pregnancy or early postpartum. Since the 16-kDa fragment of prolactin has been identified as a key factor in the pathophysiology of PPCM, prolactin inhibitors have been used as an adjuvant to standard heart failure treatment. Although bromocriptine is the current first choice, promising results have been reported with cabergoline, albeit scant.

Case Presentation

We presented the case of a 41-year-old woman who received a diagnosis of PPCM one week after delivery and was successfully treated with cabergoline, finally experiencing a complete recovery.

Conclusion

The case adds to the scant evidence supporting the use of cabergoline in PPCM patients. We argue that the favorable pharmacokinetic and metabolic profiles of this drug should prompt its consideration as a valid alternative prolactin inhibitor in these critical patients.

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Peripartum cardiomyopathy is a rare and life-threatening form of dilated cardiomyopathy.

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The management relies on the standard recommendations for heart failure with systolic dysfunction.

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The use of prolactin inhibitors represents the only specific and evidence-based treatment available.

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Given the favorable pharmacokinetics, cabergoline should be considered as the first-line prolactin inhibitor.

Less known aspects of central hypothyroidism: Part 1 - Acquired etiologies

Central hypothyroidism (CH) is a rare cause of hypothyroidism. CH is frequently overlooked, as its clinical picture is subtle and includes non-specific symptoms; furthermore, if measurement of TSH alone is used to screen for thyroid function, TSH concentrations can be normal or even above the upper normal reference limit. Indeed, certain patients are at risk of developing CH, such as those with a pituitary adenoma or hypophysitis, those who have been treated for a childhood malignancy, have suffered a head trauma, sub-arachnoid hemorrhage or meningitis, and those who are on drugs capable to reduce TSH secretion.

Circulating thyrotropin is upregulated by estradiol

After encountering two women with serum thyrotropin (TSH) levels greater in periovulatory phase than in other days of the menstrual cycle, we hypothesized that TSH levels could be sensitive to changes in circulating estrogens in women.

The objective of this study was to evaluate whether serum TSH increases after an induced acute increase of serum estradiol, and compare serum TSH increase with that of prolactin (PRL) which is a classic estradiol-upregulated pituitary hormone.

In this retrospective study, we resorted to stored frozen sera from 55 women who had undergone the GnRH agonist (buserelin)-acute stimulation test of ovarian steroidogenesis. This test, that is preceded by dexamethasone administration to suppress adrenal steroidogenesis, had been performed to show an increased buserelin-stimulated response of 17-hydroxyprogesterone, a response that is frequent in polycystic ovary syndrome. Fifty-five women had enough serum volume at pertinent times (first observation early in the follicular phase and all times of the test) to permit assay of serum estradiol, TSH and PRL.

Before dexamethasone administration, estradiol averaged 26.4 ± 15.5 pg/ml (reference range 23–139, follicular phase), TSH 1.78 ± 0.86 mU/L (reference range 0.3–4.2) and PRL 409.4 ± 356 mU/L (reference range 70.8–556) (mean ± SD).

Serum estradiol, TSH and PRL averaged 47.2 ± 27 pg/ml, 0.77 ± 0.48 mU/L and 246.4 ± 206.8 mU/L just prior to the buserelin injection, but they peaked at 253.4 ± 113.5 pg/ml (nv 83–495, midcycle), 3.30 ± 1.65 mU/L and 540.3 ± 695.2 mU/L after injection. The responses to buserelin of estradiol, TSH and PRL were of wide magnitude. There was a significant correlation between TSH peak and serum estradiol peak, betweeen AUC0-24 h-TSH and AUC0-24 h-estradiol, or between PRL peak and estradiol peak and AUC0-24 h -PRL and AUC0-24 h-estradiol in only a subgroup of women.

Therefore, women with estradiol-dependent increase in serum TSH do exist. Reference bands of serum TSH dependent on the phases of the menstrual cycle should be available.

Transcriptomics analysis and hormonal changes of male and female neonatal rats treated chronically with a low dose of acrylamide in their drinking water

Acrylamide is known to produce follicular cell tumors of the thyroid in rats. RccHan Wistar rats were exposed in utero to a carcinogenic dose of acrylamide (3 mg/Kg bw/day) from gestation day 6 to delivery and then through their drinking water to postnatal day 35. In order to identify potential mechanisms of carcinogenesis in the thyroid glands, we used a transcriptomics approach. Thyroid glands were collected from male pups at 10 PM and female pups at 10 AM or 10 PM in order to establish whether active exposure to acrylamide influenced gene expression patterns or pathways that could be related to carcinogenesis. While all animals exposed to acrylamide showed changes in expected target pathways related to carcinogenesis such as DNA repair, DNA replication, chromosome segregation, among others; animals that were sacrificed while actively drinking acrylamide-laced water during their active period at night showed increased changes in pathways related to oxidative stress, detoxification pathways, metabolism, and activation of checkpoint pathways, among others. In addition, thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were increased in acrylamide-treated rats sampled at night, but not in quiescent animals when compared to controls. The data clearly indicate that time of day for sample collection is critical to identifying molecular pathways that are altered by the exposures. These results suggest that carcinogenesis in the thyroids of acrylamide treated rats may ensue from several different mechanisms such as hormonal changes and oxidative stress and not only from direct genotoxicity, as has been assumed to date.

Acute hormonal response to glucose, lipids and arginine infusion in overweight cats

In cats, the incidence of obesity and diabetes is increasing, and little is known about specific aspects of the endocrine control of food intake in this species. Recent data suggest that ghrelin has an important role in the control of insulin secretion and vice versa, but this role has never been demonstrated in cats. Here we aimed to improve our understanding about the relationship between insulin, amylin and ghrelin secretion in response to a nutrient load in overweight cats. After a 16 h fast, weekly, six overweight male cats underwent randomly one of the four testing sessions: saline, glucose, arginine and TAG. All solutions were isoenergetic and isovolumic, and were injected intravenously as a bolus. Glucose, insulin, acylated ghrelin (AG), amylin and prolactin were assayed in plasma before and 10, 20, 40, 60, 80 and 100 min after the nutrient load. A linear mixed-effects model was used to assess the effect of bolus and time on the parameters. A parenteral bolus of glucose or arginine increased insulin and ghrelin concentrations in cats. Except for with the TAG bolus, no suppression of ghrelin was observed. The absence of AG suppression after the intravenous load of arginine and glucose may suggest: (1) that some nutrients do not promote satiation in overweight cats; or that (2) AG may be involved in non-homeostatic consumption mechanisms. However, the role of ghrelin in food reward remains to be assessed in cats.