Autoimmune hypophysitis (lymphocytic hypophysitis)

Autoimmune hypophysitis affects the pituitary gland, the small hormone-control center at the base of the brain. The immune system is thought to drive inflammation of the gland, seen as dense lymphocytic infiltration on biopsy, which can cause the pituitary to swell and then produce too little of one or more of its hormones, a pattern called hypopituitarism. Because the pituitary directs the thyroid, adrenal, and reproductive hormone systems, its effects can ripple outward into several other glands at once. It is particularly associated with pregnancy and the postpartum period, and research notes that other autoimmune conditions coexist in roughly a quarter to half of cases.

Autoimmune hypophysitis is considered a rare disease, with some estimates placing incidence around 1 case per 9 million people per year, and a review of published cases through 2004 identified only a few hundred documented patients worldwide.

Common signs

headache, vision changes, fatigue, and signs of low downstream hormones such as missed periods, low libido, low thyroid or low adrenal symptoms; if the back of the pituitary is involved, excessive thirst and urination (central diabetes insipidus).

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.