Endocrine Abstracts

Lymphocytic hypophysitis is a rare inflammatory disease of the pituitary gland. The aetiology is unknown though probably of autoimmune origin.

We report the case of a 40 year-old woman who presented 39/40 weeks pregnant with an inferior bitemporal homonymous quadrantinopia. She had primary hypothyroidsim and had had previous unsuccessful in-vitro fertilisation, though this conception was spontaneous. Magnetic resonance imaging (MRI) demonstrated a large pituitary tumour with lateral and suprasellar extension. There was compression of the optic chiasm. Within 48 hours of presentation the patient went into spontaneous labour and delivered a healthy baby. Full anterior pituitary function testing had not been possible prior to delivery though the labour was covered with hydrocortisone. After delivery it was planned that her pituitary activity be suppressed and breast milk production inhibited with Cabergoline. Her visual field defect resolved within weeks of delivery. Anterior pituitary function was later determined to be normal. A repeat MRI 4-weeks post-partum demonstrated a minimally enlarged pituitary gland and no optic nerve compression. She continues to have normal pituitary function. A clinical and radiological diagnosis of lymphocytic hypophysitis was made.

Lyphocytic hypophysitis has a striking female predilection with presentation sometimes during pregnancy or in the immediate postpartum period. Clinical presentation and radiological findings may mimic pituitary macroadenoma with or without hypopituitarism and diabetes insipidus.

Lymphocytic hypophysitis should be considered in the differential diagnosis of any pituitary lesion presenting in women during pregnancy. Features consistent with the diagnosis should be identified in order that aggressive and unnecessary pituitary surgery is avoided. Presentation in late pregnancy necessitates careful management particularly with respect to inadequate adrenal reserve during labour and the emotive issues of breast-feeding.