Lymphocytic hypophysitis (LyH) is a rare inflammatory disease, considered to be autoimmune. LyH has mainly been reported in females and in relation to pregnancy or the post-partum period. We describe a 73-yr-old woman and a 63-yr-old male who were evaluated at our clinic because of pituitary hormone deficits. Both patients had pituitary masses suggestive of a pituitary adenoma on magnetic resonance imaging (MRI). Transsphenoidal pituitary surgery was performed and histopathological examinations revealed LyH in both cases. Clinical, laboratory, radiological and the histopathological findings in these two patients are discussed in detail. In addition, we report on a 79-yr-old man with partial hypopituitarism and empty sella. Screening of a human pituitary cDNA library with his serum revealed autoantibodies against secretogranin II. This is a protein commonly present in human gonadotrophs, thyreotrophs and corticotrophs. Since the patient selectively showed the corresponding pituitary insufficiencies, we speculate on an autoimmune background. Further studies may ascertain the importance of secretogranin II autoantibodies as markers for LyH.