Endocrine Abstracts

Introduction: The pseudo-tumoral lymphocytic adénohypophysitis is an autoimmune disorder responsible for anterior hypophysis insufficiensy.It is a rare cause of pituitary hypofunction which predominantly affects young women in the peripartum period. We report the case of a patient in whom the pseudo-tumoral lymphocytic adénohypophysitis was the cause of a pituitary failure.

Case presentation: The patient was a 44 year-old woman, who presented with headache and vomiting without visual disturbance at the 7 th month of pregnancy. She was admitted to our institution in post-partum for secondary amenorrhea combined with the absence of lactation without diabetes insipidus.In the hormonal evaluation, we have a ante-pituitary insufficiency with: cortisol =0,01ug/dl, Estradiol=16pg/ml FSH=5.85 mUI/ml, LH=0.4 mUI/ml, TSH=0.008 uUI/ml, T4=2.19 ng/dl and a prolactin=0.15 ng/ml. Magnetic resonance (MR) imaging of the pituitary revealed a pituitary mass (18×14 mm) evoking a pituitary adenoma. The patient is maintained on oral hydrocortisone and thyroxine. The evolution was favorable and the controlled pituitary MRI, two years after, showed a normal pituitary gland with disappearance of the pituitary mass.

Discussion: The pseudo-tumoral lymphocytic adénohypophysitis is a rare and previously under-recognised disorder, most commonly affecting young females in the post-partum period. It presents clinically with symptoms and signs related to either a pituitary mass or hypopituitarism, frequently mimicking a pituitary adenoma. It is difficult to distinguish lymphocytic hypophysitis from a pituitary adenoma on pre-operative imaging and definitive diagnosis rests on histology which classically demonstrates destruction of anterior pituitary acini by an inflammatory infiltrate rich in plasma cells and T lymphocytes.