[Intra-sellar non-adenomatous expansive process]

More than thirty types of tumors in the sellar region can mimic pituitary adenoma on, magnetic resonance imaging. When they exist, clinical manifestations are not necessarily highly contributive to diagnosis. Headache, visual impairment, signs of antepituitary insufficiency or possible dysmenorrhea with galactorrhea attributed to hyperprolactinemia due to compression of the dopaminergic axis are not specific and may be misleading. Clinical signs of diabetes insipidis and polyphagia are however suggestive of non-pituitary tumors. Consequently, high-resolution imaging (MRI) and sometimes particular diagnostic circumstances (post partum for hypophysitis for example, or breast cancer for metastasis) orient the diagnosis. More rarely tumor enlargement, for example in certain germ cell tumors, provides a clue.