We present the case of a 76 year old woman who was admitted to our hospital with severe Cushings syndrome, in association with hair loss and hypokalaemia. Plasma cortisol levels were elevated, and did not suppress with high dose dexamethasone. ACTH levels were detectable throughout the HDDST. MRI pituitary and CT adrenals were normal, but CT of chest revealed an area of nodularity in the right lung. With no specific treatment her symptoms settled, and her biochemistry returned to normal. Three months later her symptoms recurred, and she was again found to have elevated plasma cortisol and ACTH levels with low serum potassium. Petrosal sinus and peripheral venous sampling did not identify a clear source of ACTH release. CT chest revealed an area of nodularity in the right lung. Endotracheal bronchoscopy was normal, but pathology of trans-bronchial biopsy showed features in keeping with diffuse pulmonary neuro-endocrine cell hyperplasia. Her symptoms of Cushings syndrome failed to settle with medical therapy, and ultimately she proceeded to bilateral laparoscopic adrenalectomy, with full resolution of the features of cortisol excess. Subsequent Video Assisted Thoracic Surgery (VATS) revealed diffuse nodularity throughout the right lung. Wedges were taken from middle and lower lobes, and pathology demonstrated diffuse neuroendocrine cell hyperplasia, with positive immunohistochemistry for ACTH. She remains symptomatically well since bilateral adrenalectomy. ACTH levels remain detectable, and she is currently being treated with a sustained release somatostatin analogue.
Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) is a rare pulmonary condition, pathology of which represents a spectrum of cellular hyperplasia ranging from neuro-endocrine cell proliferation to discrete masses greater than 5 mm, which may be defined as carcinoid tumours. This case represents a patient with intermittent ectopic ACTH release presenting as cyclical Cushings syndrome from DIPNECH, an association that has not previously been recognised.