Endocrine Abstracts

We present the case of a 53-year-old lady who was recently diagnosed with Type 2 Diabetes, Hypertension and Dyslipidaemia. She was referred by the lipid clinic with a 3-month history of progressive facial swelling, hyperpigmentation and proximal myopathy. Clinical history and examination were highly suspicious of endogenous hypercortisolaemia. An initial overnight dexamethasone suppression test yielded an elevated morning cortisol (752 nmol/l, normal <50nmol/l). Two 24-hour urine collections revealed markedly elevated urinary free cortisol values (1917nmol/day, 1511 nmol/day). The low-dose dexamethasone suppression test demonstrated an inability of cortisol suppression (basal cortisol 606 nmol/l, Time =48 hours 642 nmol/l), accompanied by a high ACTH (basal 48.5 ng/l, Time = 48 hours 49.5 ng/l) indicating ACTH-dependent Cushing’s syndrome. Ketoconazole therapy was commenced to alleviate hypercortisolaemia, alongside anti-hypertensive and glycaemic agents. This was beneficial for blood pressure and glycaemic management. An MRI adrenal scan showed bulky adrenal glands with no discrete lesion. An MRI Pituitary showed increased size and heterogeneity of the signal at the left lateral aspect, with infundibulum deviation to the left; however, no discrete lesion or contrast-enhancing characteristics were identified. The patient underwent inferior petrous sinus sampling which did not show a central-to-peripheral ACTH gradient, in keeping with an ectopic source of ACTH. Upon review of previous imaging performed to look for unrelated coronary artery calcification, the presence of a small 6mm lesion was noted in the Lingula of the lung. In light of the clinical, radiological, and IPSS findings, a Gallium-68 DOTATATE PET scan was performed, confirming the presence of an 8mm tracer-avid carcinoid nodule in the lingula believed to be the source of the ectopic ACTH production (not amenable to biopsy but resectable). Ketoconazole was stopped prior to surgery and the patient underwent a left VATS lingulectomy and lymphadenectomy for resection of the nodule, staged as T1a N0 PL0 R0, with histology findings consistent with Carcinoid. Postoperatively, the hypercortisolaemia improved (morning cortisol of 45 nmol/l). She was provided with steroid cover and the prednisolone was weaned following surgery. She has remained stable with satisfactory blood pressure and glycaemic control: her symptomatology has additionally improved. Ectopic ACTH secretion is a rare condition which accounts for approximately 10% of ACTH-dependent Cushing cases. This case illustrates the importance of a methodical diagnostic approach in an individual with overt clinical and biochemical hypercortisolaemia and highlights the need of an MDT approach for prompt intervention.