Endocrine Abstracts

A 50 year old man was admitted in September 2017 with left sided thoracic pain. A chest radiograph revealed a left-sided hilar mass. CT of thorax demonstrated a large, left-sided, anterior mediastinal mass with associated lymphadenopathy and sclerotic bone metastases. A CT-guided biopsy was performed and pathology was consistent with carcinoid tumour. The patient was referred to clinical oncology. An NM octreotide scan confirmed a left-sided avid lesion within the thorax. Gut hormone profile was normal. The patient was commenced on octreotide acetate injections. A follow-up CT scan was performed and the patient commenced on temozolamide as there was evidence of disease progression. The patient was re-admitted three months following the initiation of octreotide therapy with polyuria, polydipsia and hyperglycaemia consistent with diabetes mellitus. This was managed with twice daily insulin and metformin. Despite lacking symptoms of Cushing’s the cortisol following overnight dexamethasone suppression test was 1878 nmol/l (ref. range <50 nmol/l). ACTH levels were 258 mU/l (ref. range <20 mU/l) and urinary cortisol was >2000 nmol/l. The presumed diagnosis was of ectopic ACTH secretion from the known carcinoid tumour. The patient was re-admitted 2 weeks later with hypokalaemia, marked proximal mypoathy and oedema consistent with cortisol excess. He was commenced on metyrapone at an initial dose of 250 mg, twice daily which was uptitrated; once the cortisol level was less than 400 nmol/l he was commenced on hydrocortisone 20 mg morning 10 mg afternoon. A sample of serial cortisol levels have been tabulated. He continues on octreotide injections, temozolamide, metyrapone and hydrocortisone, alongside twice-daily insulin and metformin.