The involvement of the hypothalamus and/or pituitary gland by granulomatous, infiltrative or autoimmune diseases is a rare condition of non-tumoral-non-vascular acquired hypothalamic dysfunction and hypopituitarism. In this paper, we present the case of a 26-year-old woman, who showed an amenorrhea-galactorrhea syndrome with hypogonadotropic hypogonadism due to an isolated hypothalamic-peduncular localization of neurosarcoidosis. Acquired GH deficiency was also demonstrated. This clinical case provided the opportunity for a review of the endocrine aspects linked to brain infiltrative diseases that may affect the hypothalamic-pituitary function, with a focus upon neurosarcoidosis. Sarcoidosis is a pathogen-free granulomatous disease that affects both the central and peripheral nervous system in 5-16% of patients. In most cases, such involvement by sarcoidosis occurs within a multi-systemic disease, but disease localization limited to the nervous system may also be observed. Endocrine manifestations of neurosarcoidosis disclose "chameleon-like" clinical pictures, which are usually expressed by the evidence of hypothalamic dysfunction, diabetes insipidus, adenopituitary failure, amenorrhea-galactorrhea syndrome, in isolated fashion or variedly combined. More rarely, inappropriate anti-diuretic hormone secretion, isolated secondary hypothyroidism, adrenal insufficiency or altered counter-regulation of glucose homeostasis have been reported. Neurosarcoidosis is often hard to diagnose, especially when the neurological localization of the disease is not accompanied by other systemic localizations or by specific signs of the disease, and when the lesion is too deep to obtain bioptic confirmation. The study of cerebrospinal fluid and blood lymphocyte sub-populations, integrated by MRI and nuclear scans (67GalIium uptake and 111Indium-pentetreotide, Octreoscan), may be helpful for a correct diagnosis. Therapy with corticosteroid and immunosuppressive drugs, such as cyclosporine A, and other treatment approaches to neurosarcoidosis are also accounted for.