Endocrine Abstracts

A 35 year-old lady presented to her local hospital with a 3 year history of fatigue, weight gain, recurrent tonsillitis and oligomenorrhoea. Examination revealed facial plethora, round facies and thin skin on the dorsum of the hand. She appeared tanned, with evidence of spontaneous bruising and difficulty standing up from a chair unaided. No striae were present. Blood pressure was 152/91 mmHg. Investigations revealed a 0900 h cortisol of 632 nmol/l (ACTH 59 ng/l) and an elevated UFC of 727 mmol/day. An ONDST failed to suppress at 520 nmol/l (0900 h ACTH 72 ng/l). A cortisol day curve showed loss of normal circadian rhythm, with cortisols ranging from 617–776 nmol/l. IGF-1 was elevated on numerous occasions, peaking at 380 microgram/l (81.2–278.1), with detectable GH of 4.43 mg/l, but without clinic features of acromegaly. MR pituitary was unremarkable. An IPSS did not show a peripheral-to-central gradient, suggesting ectopic ACTH production. The patient failed to respond both clinically and biochemically to high doses of metyrapone and was referred to our centre for further investigations. A cortisol day curve performed on a test dose of octreotide, showed an excellent biochemical response, with cortisol levels of less than 50 nmol/l. A block-and-replace regime, with octreotide and hydrocortisone, was hence commenced. No causative ectopic ACTH source was found on full scanning, including Ga-Dotatate PET-CT. However, a 12 mm enhancing lesion was seen within the left kidney, raising concerns for a possible renal cell carcinoma. The patient proceeded to left adrenalectomy and left partial nephrectomy. Histology confirmed a renal oncocytoma, with no post-operative change in cortisol levels. Long-term management options were discussed, including removal of the remaining adrenal gland. However, given that the patient was clinically well, a block-and-replace regime was opted for. Over the next few months, the pre-octreotide 0900 h cortisol rose from less than 50 nmol/l (ACTH 10 ng/ml) to133 nmol/l (ACTH 28 ng/ml). Detectable cortisol and ACTH levels could signify recovery of the HPA axis or tumour escape. A pre-octreotide ONDST showed complete cortisol suppression to 10 nmol/l, suggesting recovery of the HPA axis. The dose of hydrocortisone was tailed down until it was altogether stopped and the patient remains in clinical remission on monthly injections of octreotide. We are unaware of other cases in the literature of ectopic Cushing’s managed with octreotide, where there has been full recovery of the HPA axis. We herein discuss the implications of this treatment in the medium to long-term.