Introduction: Clinically non-functioning pituitary adenomas (NFPA) are a heterogeneous set of complex adenomas with a wide variety of immunohistochemical subtypes such as silent gonadotrope, null cell adenoma, silent corticotrope adenoma, and other silent tumors of somatotrope, thyrotrope, and lactotrope lineages. The diagnosis is established by hypothalamus-pituitary MRI, which gives the volume of the tumor, and by determining the pituitary hormones, peripheral hormones when indicated, and neurologic manifestations. In NPFA, there is neither a typical hormonal hyper secretion nor a determined clinical syndrome.