Squeezing the Pituitary Gland

A 74-yr-old female presented with a 1-yr history of tiredness, dizziness, vomiting, reduced appetite, and 9 kg of weight loss. There was no history of headache, polydipsia, or polyuria. Perimetry revealed no abnormalities. Endocrine studies showed anterior pituitary failure: TSH, 1.53 mU/liter (ref. 0.30 – 4.20); serum T4, 8.4 pmol/liter (ref. 12.0 –24.0); cortisol, 90 nmol/liter (ref. 220 –750); FSH, 4.7 U/liter (ref. 40); LH, 1.8 U/liter (ref. 40); and prolactin, 2562 mU/liter (ref. 102– 496). Subsequent magnetic resonance imaging of the brain revealed two large bilateral cavernous sinus aneurysms (Fig. 1) with the pituitary gland “squeezed” in between. Furthermore, probably due to chronic pulsatile pressure of the aneurysms, usuration of the sellar floor is present. As a result, the two aneurysms extend into the sphenoid sinus, thereby posing a significant risk for a potentially fatal nosebleed in case of rupture of one of the aneurysms. Consequently, the patient was offered a bilateral stenting procedure of the internal carotid artery (Fig. 2), with additional coiling of the aneurysms if deemed necessary. However, despite successful test occlusion of both carotid arteries, the patient refused endovascular treatment. In the meantime, the patient was discharged on hydrocortisone and levothyroxine and was doing well on the last follow-up. Although several reports have described panhypopituitarism caused by intrasellar or unilateral carotid aneurysms (1– 4), anterior pituitary failure and hyperprolactinemia caused by “squeezing” of the pituitary gland between bilateral cavernous sinus aneurysms has, to the best of our knowledge, never been described. The mechanism causing the pituitary failure and increasedprolactin level is hypothalamic or pituitary stalk compression, causing interference with the delivery of releasing and inhibiting factors to the pituitary gland (1). When there is a combination of pituitary failure and a suprasellar heterogeneously enhancing mass, aneurysms should always been ruled out. In these cases, irradiation would be of little value, and unanticipated surgery could be catastrophic (3).