Remarkable Bilateral Adrenal Nodular Hyperplasia Incidentally Found in a Patient with Subclinical Cushing's Disease Caused By an ACTH, GH and PRL Producing Pituitary Microadenoma

Presentation Number: MON 404
Date of Presentation: April 3rd, 2017

Raúl Chervin*, Magdalena Font, Eliana Sofia and Marisol Escudero
Hospital de Clínicas "José de San Martín" - University of Buenos Aires, Buenos Aires, Argentina

Abstract

Introduction: Patients with subclinical Cushing’s syndrome are frequently found as an adrenal incidentaloma (AI). However, subclinical Cushing’s disease (CD) is rarely reported. Furthermore, although it is not uncommon diffuse or nodular hyperplasia in patients with CD, there have been reported very few cases in which the diagnosis was reached after having found an AI. Clinical report: 51 year obese male with long-standing hypertension who was referred for endocrinologic evaluation as a result of casual finding of bulky bilateral nodular adrenal hyperplasia. He referred a 14 kg weight gain in the last year but, beyond that, he developed ordinary life including work and physical activity. He was not depressed and denied having sexual dysfunction. Physical exam revealed satisfactory general state, abdominal obesity, normal muscle mass and strength, normal thyroid as well as normal 15-20 ml testicles. He showed no specific signs of Cushing's syndrome or those of any other hormonal dysfunction. His blood pressure was adequately controlled with ACE inhibitors and diuretics and he had no diabetes or dyslipidemia. Summary of lab tests and dynamic testing: 1 mg DST: not suppressed twice (serum cortisol post dexametasone: 5.5 and 15.3 μg/dl); normal ACTH levels (in a range of 18 to 45 pg/ml by seven measurements); 24 hours UFC: twofold increased twice (but once normal); night salivary cortisol: increased or within normal range; consistently increased night UFC (10 to 11 p.m.); normal urinary metanephrines; Aldosterone / PRA: indicative of secondary aldosteronism; mild hyperprolactinemia; pronounced secondary hypogonadism - [testosterone]: 1 ng/ml - ; [IGF-1]: raised 1.2 and 1.8 times. Pituitary MRI revealed the image of a 6.8 mm pituitary adenoma. Since 8 mg DST showed 62% suppression but there was a non responsive desmopressin stimulation test, inferior petrosal sinus sampling was performed which showed a high central to peripheral ACTH gradient indicative of a pituitary source. Treatment and outcome: By transsphenoidal microsurgery it was removed a pituitary microadenoma with ACTH, GH and PRL positive immuno-staining. The development of postoperative adrenocortical failure with normalization of other pituitary axes was confirmatory of surgical success and proper diagnosis. Conclusions: 1) To the extent nodular hyperplasia is more common in long-standing CD, this could have been the case of our patient with probable diagnosis delay due to attenuated clinical expression of his cortisol excess. 2) Insofar as 11βHSD–1 activity is inhibited by excess GH it is possible to hypothesize that in this patient, carrying a hyperfunctioning multi-hormonal adenoma, hypercortisolism could have been masked, at least partially, by an apparently mild GH hypersecretion. 3) Our case also stresses the importance of reliably measuring ACTH in bilateral AI patients with subclinical Cushing's syndrome.

 

Nothing to Disclose: RC, MF, ES, ME