Endocrine Abstracts

Introduction: Biochemical assessment of incidental adrenal nodules is increasingly performed prior to clinical review. Occasionally, serendipitous diagnoses can result. Here we discuss two patients with adrenal nodules where additional endocrine testing both helped and hindered diagnosis, respectively.

Case details: Case 1 A 52-year-old man was referred following incidental detection of bilateral adrenal nodules. There were no clinical examination features of endocrinopathy. Biochemical evaluation demonstrated a non-suppressed cortisol level following dexamethasone administration (53 nmol/l); Opportunistic urine steroid profile testing revealed increase metabolites of 17-hydroxyprogesterone (17-OHP) in-keeping with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. Diagnosis was confirmed with Synacthen stimulated 17-hydroxyprogesterone and the patient was counselled and offered genetic testing. The adrenal lesions were deemed representative of underlying adrenal hyperplasia. Case 2 A 55-year-old lady was referred with incidental bilateral adrenal. Clinical examination revealed elevated body mass index but no definite stigmata of Cushing’s syndrome. Baseline biochemical evaluation (plasma metanephrines, aldosterone, plasma renin activity, androgen profile and overnight dexamethasone suppression test) were normal but ACTH was markedly elevated at 282 ng/L (0-46). Low dose dexamethasone suppression and urine cortisol were normal. Assay interference was considered and alternative assay testing revealed normal ACTH levels of 27 ng/L (7.2-63.3). Follow-up 6-month interval imaging revealed stable appearances of the adrenal nodules, and the patient was discharged from follow-up.

Discussion: Wider hormone testing for incidental adrenal nodules may identify rare conditions early. However, managing unexpected findings can be challenging. Careful test selection is advisable and knowledge of the relative strengths and limitations of tests used is essential. Including an androgen profile or urine steroid profile can be beneficial but requires caution due to potential false positives.