Cushing’s Syndrome: Clinical Perspectives

Abstract

A 45-year-old woman presented with weight gain, oligomenorrhea, easy bruising, and generalized weakness for the last 2 years. She was a known hypertensive for the last 8 years and diabetic for the past 2 years. On examination, she had BMI 30 kg/m2, blood pressure 160/100 mm Hg, and had florid features of Cushing’s syndrome including facial plethora, wide violaceous striae, cuticular atrophy, bruise, and proximal myopathy. She had hyperpigmentation of knuckles. Her Ferriman–Gallwey score was 20/36 and had no features of virilization. On biochemical evaluation, serum potassium was 4.8 mEq/L, and liver and renal function tests were normal. Fasting plasma glucose was 200 mg/dl, postprandial plasma glucose 260 mg/dl, and HbA1c 9.5%. Lipid profile revealed high triglycerides and low HDL-C. Cortisol dynamics showed 0800h cortisol 770 nmol/L, awake 2300h cortisol 667 nmol/L, 0800h ACTH 45 pg/ml, overnight dexamethasone suppression test (ONDST) 406 nmol/L, low-dose dexamethasone suppression test (LDDST) 375 nmol/L, and high-dose dexamethasone suppression test (HDDST) 127 nmol/L. Serum prolactin was 8.1 ng/ml, T4 8 μg/dl, TSH 2.1 μIU/ml, testosterone 2.6 nmol/L, LH 1.1 μIU/ml, and FSH 2.1 μIU/ml. Compression ultrasonography of lower limb was normal, and DXA scan showed osteoporosis (T-score –2.6 and Z-score -3 at lumbar vertebra). Dynamic contrast-enhanced MRI of sella revealed 4.8 mm adenoma on right half of pituitary. She underwent bilateral inferior petrosal sinus sampling (IPSS) with AVP stimulation (10 IU i.v. infusion). IPSS localized the source of ACTH excess to pituitary gland and lateralized to right half of pituitary gland. As patient had right hypochondrial pain, CECT abdomen was done, which demonstrated a left adrenal mass measuring 2.5 × 2 cm and bulky right adrenal. As she had osteoporosis, she was treated with calcium, vitamin D, and zoledronic acid. She underwent transsphenoidal surgery after optimal blood glucose and blood pressure control. Postoperatively, her day 2 serum 0800h cortisol was 84 nmol/L. She did not have any complications after surgery. She was initiated on hydrocortisone replacement. Histopathology showed pituitary adenoma on ACTH immunopositivity. At 6 weeks, she had a weight loss of 6 kg, resolution of plethora, and reduction in the requirement of antihypertensives. She had normal plasma glucose profile without any medications. Her serum 0800h cortisol was 120 nmol/L after omission of hydrocortisone for 24 h, and serum T4 was 6 μg/dl. At three months of follow-up, she is in remission and is doing well.