Abstract #1405095: PCOS Diagnosis Leading to a Delayed Diagnosis of Cushing's Disease

Abstract

Polycystic ovarian syndrome (PCOS) is a common disorder affecting pre-menopausal women. Diagnostic criteria for PCOS include menstrual irregularities, biochemical or clinical hyperandrogenism and/or evidence of polycystic ovaries on ultrasound. Any 2 of the above is sufficient for a diagnosis of PCOS. However, PCOS is a diagnosis of exclusion so other pathologies should be investigated including hypercortisolemia. We present a case of Cushing's Disease in which the patient’s clinical features were previously attributed to a diagnosis of PCOS delaying appropriate intervention. A 22-year-old nulligravida woman with no significant past medical history presented to the Ob/Gyn clinic with complaints of amenorrhea and infertility. Patient noted irregular menstrual cycles since attaining menarche, she denies any headaches, galactorrhea but reported facial hirsutism and weight gain. She was initially diagnosed with PCOS but had continued amenorrhea despite treatment with medroxyprogesterone acetate. Additional work up was ordered by Gyn which noted mildly elevated Prolactin at 30.84 ng/ml. MRI head/brain subsequently ordered noted a large T2 weighted hyperintense lesion measuring 2.2 x 1.65 x 2.0 cm involving the sella with extension suggesting a pituitary macro-adenoma. Patient was referred to endocrinology for additional work up. Further evaluation showed normal repeat prolactin level with dilution study normal at 11.9 ng/ml. She was found to have secondary hypogonadism with FSH - 5.32 mIU/ml, LH- 2.1IU/L and estradiol level at < 20 pg/ml. She also had secondary hypothyroidism with TSH 0.88 mIU/ml and free T4 at 0.64 ng/dl. Morning Cortisol was at 19.13 ug/uL with baseline ACTH elevated at 127 pg/ml. This showed adequate adrenal function but concern for ACTH dependent hypercortisolemia. She had 2 failed 1 mg dexamethasone suppression test with cortisol level at 10.92 ug/uL and 20.91 ug/uL with adequate dexamethasone levels. She had 2 elevated 24-hour urine cortisol at 72ug/24hr and 81ug/24hr. She also had 2 elevated midnight salivary cortisol level at 0.338ug/dl and 0.349ug/dl. Other labs showed normal IGF-1 and normal DHEA-S. Patient was diagnosed with Cushing Disease and underwent successful transsphenoidal resection of the pituitary macroadenoma. Post operative cortisol was <2 ug/ul, she was initiated on hydrocortisone 20mg am and 10mg pm. Patient had continued monitoring for recovery of hypothalamic-pituitary-axis. A month after the surgery, patient got pregnant and was continued on her hydrocortisone and levothyroxine replacement. In our case the diagnosis and treatment of Cushing's disease was delayed due to clinical features mimicking PCOS. PCOS is a diagnosis of exclusion, and our case illustrates the importance of excluding the other endocrine pathologies, such as Cushing's disease, to prevent delaying the appropriate treatment and to mitigate the risk of increased morbidity and mortality that may be associated with them.