Endocrine Abstracts

Case: A 46-year-old woman was initially investigated for right sided intermittent headaches for one year. Her MRI head revealed a pituitary adenoma. She had no history of vomiting with the headache episodes and had no history of visual acuity or field defect. She had amenorrhoea for the past 10 months. Prior to this, she had regular periods following her menarche at the age of 12 years. She admitted to easy bruising but had no hirsutism or acne. She did not report any weight gain. Her past medical history is significant for type 2 diabetes diagnosed April 2017 and managed with metformin. The patient is a non-smoker and does not drink alcohol. On examination, she had a raised BMI with a weight of 77.9 kg and sitting BP of 132/93 mmHg. She had a round face and central adiposity. There were pale striae on her lower abdomen and she had acanthosis nigricans around her neck. There was no evidence of proximal myopathy.

Investigations revealed state of hypercortisolemia with failure to suppress morning cortisol in both overnight dexamethasone and low dose dexamethasone suppression tests, 136 and 138 nmol/l respectively. Also she was found to have three sets of elevated late night salivary cortisol. Cortisol Day curve demonstrates no diurnal variation in endogenous cortisol production with cortisol levels range between 313 and 368 nmol/l between 9 am and 6 pm. Her midnight serum cortisol was elevated at 377 nmol/l. Dedicated Pituitary MRI showed a central and left-sided adenoma measuring 15 mm by 9 mm in maximal axial dimensions. There was suprasellar extension with distortion of the pituitary infundibulum to the right. The adenoma extended to the under surface of the optic chiasm and marginally elevated left sided optic chiasm without overt compression. Subsequent bilateral petrosal sinus sampling excluded ectopic ACTH with a basal IPS:P (central: peripheral) ratio > 2.0 and a CRH stimulated IPS: P ratio >3.0 (Table 1).

Treatment: The patient was started on Metyrapone to control hypercortisolemia till she had surgery. Also, she was initiated on anticoagulation with Tinzaparin.

Discussion Points:

-Investigation of Cushing’s disease (Tests and Interpretation)

-Bilateral petrosal sinus sampling indication, interpretation and limitation

-Medical management of Cushing’s disease and the importance of thromboembolism prophylaxis.