Pituitary Apoplexy After Post-Obstructive Diuresis in a Patient with Known Pituitary Macroadenoma

Pituitary apoplexy is a clinical syndrome due to abrupt hemorrhage and/or infarction of the pituitary gland, generally within a pituitary adenoma.  The most common symptoms are acute onset of headache, visual disturbances or ocular palsy.  Diagnosis of pituitary tumor is often not known at the time of apoplexy.  Risk factors for pituitary apoplexy include cerebral angiography, head trauma, dynamic endocrine testing, such as insulin tolerance test, surgery (especially cardiac and orthopedic), treatment with GnRH agonists for prostate cancer, and anticoagulation.  Peri-operative hypotension and micro-emboli formation during surgery can lead to pituitary infarction.

Case Description :

This is an 80 year old man with history of non-functional 2 cm left pituitary macroadenoma with cavernous sinus invasion who was admitted with acute urinary retention.  Morning cortisol on admission was normal at 14.9.  Foley was placed for urine retention, with resultant polyuria. Patient was not maintained on IV fluids during post-obstructive diuresis, and developed hypotension, along with headache, double vision, left cranial nerve IV and VI palsy, altered mental status, and lethargy.  MRI brain/pituitary showed pituitary infarction and chronic occlusion of left internal carotid artery.  Urgent p</span>ituitary function labs and random cortisol were obtained, and patient was started on IV hydrocortisone, with significant improvement in his blood pressure and mental status.  Labs prior to steroids showed random cortisol low at 1.6, ACTH < 5.0, TSH 1.1, and free T4 low at 0.35.  He did not require surgery, and was discharged to subacute rehab on oral hydrocortisone and levothyroxine.  Repeat outpatient MRI pituitary one month later was stable.   He was given a 1-week dexamethasone taper, with resolution of left cranial nerve IV and VI deficits documented on before and after photos.  Levothyroxine dose was tapered to 50 mcg daily as an outpatient.

Discussion :

Patients with pituitary macroadenoma should be monitored closely when admitted to the hospital or undergoing surgery, to decrease the risk of apoplexy.  Hypotension should be avoided, whether in the perioperative setting, or in the setting of volume depletion and sepsis.  Due to it being relatively rare, pituitary apoplexy is often underrecognized.  In severe cases, it is a medical and surgery emergency, due to acute pituitary hormone insufficiencies, and increased intracranial pressure, which can lead to permanent neurologic injury or death.  In this patient with post-obstructive diuresis after foley placement for acute urinary retention, early recognition of patient’s history of pituitary macroadenoma and risk for apoplexy, careful monitoring of ins and outs, and aggressive fluid replacement may prevent acute pituitary hormone insufficiencies and ocular nerve palsies from occurring.