Endocrine Abstracts

57 year old female physiotherapist, diagnosed with osteoporosis following a fibula fracture from a low impact stretch and a wedge vertebral fracture at age 51 with a metatarsal fracture age 54. With associated history of easy bruising, increase abdominal girth although her weight remained stable at 48.5 kg with BMI 19.9 and proximal myopathy. Blood pressure was constantly normal.

Investigations: Early morning random Cortisol 564 and ACTH 6.6 (2–11), cortisol after overnight 1 mg Dexamethasone Suppression test 35. Long Dexamethasone Suppression Test (2 mg QDS) baseline cortisol level 353 post-test cortisol suppressed to 38.6 9 am salivary cortisol 183(5–46). MRI showed a bulky pituitary and no macroadenomas although a microadenoma could not be excluded. Pituitary MRI with contrast showed two focal area of hypo-enhancement within the left anterior aspect of the pituitary which measured 2.7 x 5.2 and 2.5 mm x 6.0 mm and was cystic in nature. Repeat ACTH was 9 pmol/l. CT Thorax, abdomen and pelvis demonstrated no adrenal masses. 24 Hour Urinary free cortisol 479 and 274 a few months apart when she had maximal symptoms (Ref range <165). The rest of the pituitary profile was normal. Electrolytes were consistently normal. IPSS done showed significant gradient between the right side of the pituitary and peripheral ACTH. She had transsphenoidal surgery unfortunately her symptoms persisted. Post transsphenoidal surgery MRI head showed a hypo enhancing focus within the pituitary gland anteriorly at and just to the left of the midline. Appearance compatible with residual recurrent adenoma. 24hour Free Urinary cortisol was 467. She was commenced on Metyrapone awaiting second transsphenoidal surgery. Metyrapone was adjusted according to hydrocortisone day curve. The second transsphenoidal surgery was successful, ACTH 0.7 24 hour urinary cortisol 72.7 TSH 1.1 early morning cortisol 22.5. Histology showed corticotroph adenoma. She was commenced on replacement hydrocortisone. Generally, her symptoms improved, unfortunately she never regained her health.

Discussion: Cushing’s disease is challenging to diagnose and manage. Transsphenoidal surgery provides initial cure for 75 to 90% and recurrence in 5 to 20% of cases. Residual tumour on MRI repeat transsphenoidal surgery 50 -70% cure 1. Residual tumour which is non resectable, pituitary irradiation and steroidogenesis inhibitor with 85 to 100% cure rate. Bilateral adrenalectomy, in cases of severe hypercortisolism or women desiring pregnancy with a potential cure rate of 100%. Patients with mild hypercortisolism can be treated with corticotrope-directed medical therapy (pasireotide or Cabergoline) with possible 20 to 40% remission.