ECE2015 Eposter Presentations Clinical Cases–Pituitary/Adrenal (95 abstracts)
1Erasme University Hospital, Brussels, Belgium; 2INSERM, U982, University of Rouen, Mont-Saint-Aignan, France; 3Jules Bordet Institut, Brussels, Belgium.
Introduction: Aberrant expression of serotonin receptors has been described to be involved in the pathophysiology of both aldosterone-producing and cortisol-producing adrenal adenomas.
Case report: A 46-year-old woman was referred for evaluation of severe hypertension associated with hypokalaemia. Primary aldosteronism with concurrent subclinical Cushings syndrome was diagnosed. A CT-scan identified a lesion of 4 cm in the right adrenal gland and a second lesion of 1 cm in the left adrenal gland, both displaying benign imaging phenotype. Following dexamethasone suppression, we explored the potential aberrant expression of serotonin receptors in the adrenal cortex by intravenous administration of metoclopramide, a serotonin type 4 receptor (5-HT4-R) agonist. This led to abnormal cortisol increase and physiological response of aldosterone in peripheral blood. Adrenal venous sampling was then performed in basal conditions and after metoclopramide stimulation. An increase in cortisol level was observed in the left adrenal vein after stimulation. 131I-19-Iodocholesterol scintigraphy showed intense radiotracer uptake in the right adrenal mass and weak uptake in the contralateral mass. Right laparoscopic adrenalectomy was performed. Histological examination revealed an adrenocortical adenoma. In vitro, cultured adrenocortical cells derived from the tumoural tissue exhibited aldosterone and cortisol co-secretion. Administration of 5-HT or metoclopramide to the cells induced a dose-dependent increase in cortisol production. These effects were inhibited by concomitant administration of the 5-HT4-R antagonist GR113808. Incubation of tumour tissue fragments with 5-HT induced a significant increase in aldosterone production which was abrogated in the presence of GR113808. These data were suggestive of aberrant expression of 5HT4-R in the tumoural tissue.
Conclusion: We report a rare case of an aldosterone- and cortisol-co-producing adenoma in a patient with severe hypertension and bilateral adrenal masses exhibiting an abnormal plasma cortisol response to metoclopramide. In vitro studies revealed enhanced sensitivity of the tumour tissue to 5-HT indicative of illicit expression of 5-HT4 receptors.