Lymphocytic hypophysitis is a rare neuroendocrine disorder characterized by pituitary infiltration by T and B lymphocytes, often presenting with hypopituitarism. While the incidence was previously estimated at 1 in 9 million, recent studies suggest that this might be an underestimation. To our knowledge, no published case has been reported yet among Filipino patients. Traditionally associated with women in the 3rd trimester or postpartum, lymphocytic hypophysitis has been shown to affect both non-pregnant women and men, with a mean age of diagnosis around 34 years.

This case reports a 59-year-old Filipino woman presenting with two-month history of blurred vision and headaches. Recurring symptoms prompted consult with a neurologist. Cranial Magnetic Resonance Imaging (MRI) revealed a pituitary macroadenoma, and labs indicated central hypothyroidism and central adrenal insufficiency, with negative Antinuclear Antibodies (ANA) results.

The patient underwent transsphenoidal surgery for pituitary adenoma excision, but histopathological examination revealed lymphocytic infiltration, suggesting idiopathic lymphocytic hypophysitis. Three months post-surgery, the patient continued hormonal replacement therapy with prednisone and levothyroxine.

The rarity of lymphocytic hypophysitis poses diagnostic and treatment challenges. It should be considered a differential diagnosis of pituitary masses at any age. While transsphenoidal surgery is recommended if there is compression of nearby vital structures, conservative medical management is often the primary treatment option.