Endocrine Abstracts

Autoimmune hypophysitis is a rare disease with only 28 cases reported in UK so far. Subsequent pregnancy, especially after pituitary surgery, is even more rare. We report a 34-year-old lady who presented 5 weeks after the birth of her second child with visual loss and headache. Subsequent investigations revealed a pituitary macroadenoma with suprasellar extension and chiasmal compression. She underwent transphenoidal adenomectomy with complete recovery of vision. Preoperatively she was hypothyroid and had suboptimal cortisol reserve. Histology revealed Lymphocytic Hypophysitis.

Post-operative evaluation revealed Growth hormone deficiency, cranial diabetes insipidus, borderline cortisol reserve and normal thyroid function. She was commenced on regular desmopressin and prescribed steroids to be taken at times of stress. She continued to have regular periods and three years after her original presentation she got pregnant spontaneously. She had adequate thyroid and cortisol reserve during this pregnancy but continued to require desmopressin. There was no recurrence of her hypophysitis (the exact incidence of autoimmune hypohysitis with future pregnancies is unknown). She delivered spontaneously under steroid cover and her subsequent MRI scan revealed no change to the size of the residium.

Literature search had revealed that 12% of women became pregnant again, after their initial presentation with autoimmune hypophysitis during their previous pregnancy or post-partum period. Autoimmune hypophysitis should be considered in the differential diagnosis of any pituitary mass especially when presenting during pregnancy or post-partum. A high index of clinical suspicion is required to diagnose this condition as conservative management may eliminate the need for aggressive pituitary surgery.