Endocrine Abstracts

Case history: A 61 year old male with a background of diabetes mellitus Type 2 and congestive cardiac failure (CCF) was diagnosed with Cushing’s disease in 2014 following identification of severe osteoporosis through investigations for non-traumatic vertebral fractures causing paraplegia.

Investigations: He had high ACTH and cortisol levels which failed to suppress on low and high dose dexamethasone suppression tests, hypogonadotrophic hypogonadism and MRI imaging identified a pituitary macroadenoma with sphenoid and cavernous sinus invasion a CT scan of his chest/abdomen/pelvis was normal.

Results and treatment: He underwent transpheniodal surgical de-bulking in May 2015 (histology compatible with an ACTH staining pituitary adenoma with Ki67 index of 15%) followed by radiotherapy. He remained on hydrocortisone (HC) post-operatively, but this was withdrawn in February 2016 following a normal short synacthen test (SST). Serum cortisol levels began to rise once again to 1204 in February 2018. MRI demonstrated increase in size of the residual adenoma and metyrapone was started and titrated to 1g TDS. Due to his multiple comorbidities, with deteriorating glycaemic control, raised BMI and progressive CCF symptoms he was deemed high surgical risk and so chemotherapy with temozolomide was being considered. He presented to A&E 6 weeks later with headache, double vision and right-sided ptosis. He was found to have 3^rd, 4^th and 6^th cranial nerve palsies, with a temporal field defect and MRI demonstrated significant enlargement of the tumour with central necrosis. During this admission his glycaemic control improved leading to recurrent hypoglycemia, resulting in reduced insulin requirements and his symptoms of CCF improved without further treatment. His metyrapone dose was down-titrated and eventually stopped and two weeks later HC was reintroduced. Unfortunately in November 2018, ACTH and cortisol levels started to rise and HC was once again discontinued. Repeat MRI showed worsening of the appearances of the intracranial lesion(s), raising concerns of development of a second neoplasm.

Conclusions and points for discussion: This is a fascinating case, which demonstrates the challenges of managing Cushing’s disease due to an aggressive pituitary adenoma. During the period of surveillance nature offered a respite for his severe hypercortisolaemia when central tumour necrosis rendered him cortisol deficient but at the cost of severe ophthalmological complications (ptosis and unilateral partial blindness). He is currently off metyrapone and hydrocortisone whilst awaiting investigations to further characterise the unusual appearances of the intracranial lesions and to plan further treatment for these.