A complicated case of primary hypophysitis with bilateral intracavernous carotid artery occlusion

Primary hypophysitis (PH) is a rare clinical entity characterized by inflammatory infiltration of the pituitary gland with various degrees of pituitary dysfunction.

To present a complicated case of aggressive PH with bilateral cavernous sinuses infiltration, successfully treated with azathioprine after failure of corticosteroid treatment.

A 48-year-old woman presented with episodes of recurrent headache and progressively worsening muscle weakness. Magnetic resonance imaging (MRI) identified an intrasellar pituitary lesion with thickened pituitary stalk extending to the cavernous sinuses and causing asymptomatic occlusion of both internal carotid arteries (ICAs). Hormonal investigation showed severe anterior pituitary deficiency. The diagnosis of PH, and more specifically of lymphocytic hypophysitis (LYH), was suspected and glucocorticoid treatment was initiated. Because of the patient's susceptibility to infections, the attempt to gradually reduce glucocorticoid dosage induced a relapse of PH. Immunosuppressive therapy with azathioprine was administered. Significant pituitary mass reduction with regression of the inflammation to the cavernous sinuses was documented. At follow-up the pituitary function was normal, while the patient was on the minimum dose of azathioprine. Thereafter, azathioprine was discontinued without any clinical/biochemical or radiological evidence of PH except for the permanent ICA occlusion.

Despite its rarity, PH should be included in the differential diagnosis of pituitary masses and involvement of ICAs occlusion should not be underestimated. Azathioprine, applied as an alternative treatment, was shown to result in remarkable PH improvement.