Both endogenous and exogenous estrogens have been implicated in the precipitation of PA in women of reproductive age, particularly during the peripartum period. While reported incidences of PA in reproductive-age women on oral contraceptives (OCPs) demonstrate estrogen’s role in coagulation, little evidence exists to support similar effects of HRT in post-menopausal women. 

A previously healthy 58-year-old woman was evaluated in the emergency department for acutely altered mental status, brain fog, and emotional lability. She reported headache, tinnitus, and wordfinding difficulty at the time of symptom onset, preceded by irritability and an “out of body experience.” Head CT revealed high attenuation within the pituitary gland sella, with MRI demonstrating an 8 mm sella hyperintensity on T1 consistent with acute PA. 

Upon further investigation, the patient reported starting combined oral estrogen and progesterone HRT for menopause symptoms 45 days prior to presentation. She had 4 prior uncomplicated pregnancies, and no history of hypercoagulability or thromboembolic events. HRT was discontinued and the patient was discharged home with normal laboratory findings and no residual symptoms 2 days after admission. The patient was followed outpatient by endocrinology and neurology in the weeks following hospitalization, who noted fatigue and low morning cortisol that self-resolved. At 3 months, CT head and MRI demonstrated a small nonenhancing circumscribed nodular structure along the superior surface of the pituitary gland believed to be a pituitary microadenoma, with no residual evidence of PA. 

This case features the unique finding of PA in a postmenopausal woman on HRT in absence of known contributory factors. Despite most HRT regimens consisting of smaller doses of estrogen than OCPs, this case supports the role of exogenous estrogens in precipitating PA in post-menopausal women.