Primary (autoimmune) hypophysitis: a single centre experience.

Background: Autoimmune hypophysitis (AH) is a rare autoimmune inflammatory disorder of pituitary gland.

Objective: To analyse clinical, hormonal, radiological features and management outcomes of AH.

Design: Retrospective analysis of patients with primary hypophysitis (where secondary causes of hypophysitis were ruled out) was carried out from 2006 to 2012. AH emerged as the most plausible aetiology and the diagnosis of exclusion.

Results: Twenty-four patients with AH (21 females and 3 males) were evaluated. They presented with symptoms of expanding sellar mass (83.3%), symptoms of anterior pituitary hormone deficiencies (58.3%), and diabetes insipidus (16.7%). The anterior pituitary hormonal axes affected were cortisol (75%), thyroid (58.33%) and gonadotropin (50%). All had sellar mass on magnetic resonance imaging, which was symmetrical (91.7%) and homogenously enhancing (91.7%). Stalk thickening, suprasellar extension, loss of posterior pituitary hyperintensity and parasellar T2 dark sign were seen in 87.5, 87.5, 71.5, and 50% respectively. In addition to hormone replacement, five (20.83%) patients underwent trans-sphenoidal surgery, fifteen (62.5%) were watchfully monitored, while four cases (16.67%) received steroid pulse therapy. On follow up imaging, the sellar mass regressed in all, while, stalk thickening was persistent in 13/19 (68.4%) non-operated patients at median follow up of 1 year. Pituitary hormone axis recovery was seen in 10 (41.67%) and was seen in cortisol 10/18 (55.5%) followed by gonadotropin 5/12 (41.67%) axis.

Conclusion: Characteristic radiology helps in diagnosis of AH even without tissue diagnosis. Non-operative treatment is the preferred treatment modality. Steroid pulse therapy potentially improves pituitary axis recovery.