ectopic neurohypophysis may be accompanied by midline brain defects and some degree of endocrine disorders . the associated endocrine disease varies from isolated growth hormone ( gh ) deficiency to multiple anterior pituitary hormone deficiencies , but posterior pituitary function remains unchanged . anterior pituitary hormone deficiencies may present with varied clinical manifestations like growth failure , central hypothyroidism , or underdeveloped secondary sexual characters . at the same time , the disease starting with gh deficiency can progress to pan hypopituitarism with time . neurohypophysis is observed as a bright dot behind normal posterior lobe of adenohypophysis on t1-weighted magnetic resonance ( mri ) images . ectopic neurohypophysis is specifically monitored at the level of the median eminence of the hypothalamus in imaging studies . because of its rareness , we present radiological findings of a case that showed coexistence of ectopic neurohypophysis , corpus callosum dysgenesis , and periventricular neuronal heterotopia , with accompanying literature review . a 21-year - old female patient was admitted to the neurology clinic of our hospital with complaints of forgetfulness , twitching of eyes , and short stature . laboratory measurements for the pituitary hormones uncovered a very low level of gh ( 0.06 ng / ml ) , while the other hormones and their levels were normal [ table 1 ] . in mr images of the brain and pituitary ( 1.5-t system , ge medical systems signa , milwaukee , wi ) , the neurohypophysis was seen at the ectopic site as a bright dot at the level of the optic chiasm on coronal t1 images . infundibular part was thinner than usual [ figure 1 ] . at the same time , partial dysgenesis of corpus callosum and periventricular neuronal heterotopia were observed on the mr images [ figures 2 and 3 ] . ophthalmologic examinations for a possible involvement of the optic discs , including visual acuity test , visual field test , and dilated fundoscopy were completely normal . also , the systemic evaluation of the patient for other possible associations was normal . serum levels of anterior pituitary hormones in the patient 21-year - old female patient with complaints of forgetfulness , twitching of eyes , and short stature later diagnosed with coexistence of ectopic neurohypophysis , corpus callosum dysgenesis , and periventricular neuronal heterotopia . a coronal non - contrast t1-weighted mri image reveals a hyperintense ectopic posterior pituitary adjacent to the optic chiasm , at the level of the median eminence of the hypothalamus ( arrows ) . 21-year - old female patient with complaints of forgetfulness , twitching of eyes , and short stature later diagnosed with coexistence of ectopic neurohypophysis , corpus callosum dysgenesis , and periventricular neuronal heterotopia . sagttal t2-weighted mri image reveals partial dysgenetic view of the corpus callosum and protrusion of cingulated gyrus ( arrow ) . 21-year - old female patient with complaints of forgetfulness , twitching of eyes , and short stature later diagnosed with coexistence of ectopic neurohypophysis , corpus callosum dysgenesis , and periventricular neuronal heterotopia . axal t2-weighted mri image reveals an appearance that is compatible with periventricular - subependymal heterotopic neuronal tissue ( arrows ) . the neurohypophysis comprises the posterior pituitary lobe , the infundibulum , and the median eminence of the hypothalamus . the neurohypophysis is formed by the evagination of neural tissue from the floor of the third ventricle . it consists of the distal axons of the hypothalamic magnocellular neurones that shape the neurohypophysis . after its downward migration , it is encapsulated together with the ascending ectodermal cells of rathke 's pouch , which form the adenohypophysis . the pituitary gland acts as an endocrine gland under control of the hypothalamus via the infundibular stalk . regardless of the underlying cause , the ectopic neurohypophysis results from incomplete downward growth and fusion of the neurohypophysis with the adenohypophysis in the sella . possible pathophysiologic mechanisms for ectopic neurohypophysis development are transection of the pituitary stalk followed by hypertrophy of the proximal axons with subsequent reorganization . also trauma of the pituitary stalk due to vascular accidents , anoxia , or compression injuries have been suggested as acting through similar mechanisms leading to reorganization of the proximal neurons of the neurohypophysis . although early studies describe a traumatic cause in the etiology of the ectopic neurohypophysis , more recent studies favor a genetic basis , supported by rare familial cases of ectopic neurohypophysis . the ectopic neurohypophysis cases have been reported in idiopathic gh deficiency or in subjects with hesx1 , lhx4 , and sox3 gene mutations . again , a few earlier reports have suggested that ectopic neurohypophysis may share a similar pathogenesis as septo - optic dysplasia , which classically has features of optic nerve hypoplasia , hypothalamic - pituitary dysfunction , and agenesis of the septum pellucidum . the other well - known malformations associated with ectopic neurohypophysis include chiari 1 malformation , agenesis of the corpus callosum , persistent cranio - pharyngeal canal , kallmann syndrome , basilar impression , medial deviation of the carotid arteries , microcephaly , cerebellar atrophy , and vermian dysplasia . associated ophthalmic and midline facial abnormalities , such as a single central incisor tooth , are typical , and non - midline somatic conditions , including cardiac and musculoskeletal abnormalities , breech presentation and neonatal hypoglycemia are also commonly reported . as a result of ectopic neurohypophysis and associated stalk abnormalities , factors released by the hypothalamus , which usually travel down the portal circulation to the anterior pituitary the patients with an ectopic neurohypophysis located at the median eminence and no visible pituitary stalk present a more severe form of the disease , with multiple anterior hormone deficiencies . whereas visibility of the pituitary stalk and an ectopic neurohypophysis located at some point along the stalk is associated with isolated gh deficiency . in our patient , there were radiological findings of coexistence of ectopic neurohypophysis , corpus callosum partial dysgenesis , and periventricular neuronal heterotopia . dysgenesis of the corpus callosum represents an in utero developmental anomaly , which may be complete ( agenesis ) or partial . it may occur in isolation or in association with other central nervous system or systemic malformations . periventricular heterotopia is the most common form of gray matter heterotopia and is characterized by nodules of gray matter located immediately beneath the ependyma of the lateral ventricles . previous reports of cases with coexistent periventricular heterotopia and ectopic neurohypophysis suggest both conditions can share a common underlying causative mechanism , even though pituitary development occurs earlier in fetal life than does neuronal migration . another study has found hesx1 mutations in only 5 of 93 patients with ectopic neurohypophysis , indicating that other unrecognized genes or local environmental factors are likely to be involved in the ectopic neurohypophysis development . in ectopic neurohypophysis cases , normal neurohypophysis bright spot is absent in the sella and there is high t1 signal at the median eminence ( floor of third ventricle ) or along infundibuler stalk , instead of normal sellar position , on unenhanced t1-weighted images . infundibuler stalk may be tiny or absent . although controversy still exists on the source of this distinct signal , it has most recently been attributed to phospholipids within the walls of the secretory vesicles containing the arginine vasopressin neurophysin complex . distinction of the ectopic neurohypophysis from dermoid tumor or lipoma can be confirmed by images obtained using fat saturation . in this article , because of its rareness , we present mri findings of concurrence of ectopic neurohypophysis , dysgenesis of the corpus callosum , and periventricular neuronal heterotopia . radiologists should carefully evaluate mr images in patients with epilepsy or hormone deficiency for the possibility of ectopic neurohypophysis and neuronal heterotopia . in the presence of ectopic neurohypophysis