SUN-067 Pituitary Dysfunction in Children with Ectopic Posterior Pituitary

Background: Imaging studies aid in the detection of structural abnormalities that may be associated with pituitary dysfunction, such as ectopic posterior pituitary (EPP). The location of the ectopic lobe can vary, but it is most commonly located along the median eminence in the floor of the third ventricle. An EPP could result from complete or partial defective neural migration during embryogenesis, which could explain the different loci of EPP. Affected individuals have either severe isolated growth hormone deficiency (IGHD) or combined pituitary hormone deficiencies (CPHD); diabetes insipidus is not a feature, indicating that the EPP is functioning normally. Aim: To detect the prevalence of IGHD or CPHD in children with EPP. In addition, to evaluate the association between the location of EPP and pituitary dysfunction. Methods: A retrospective chart review of MRI reports at St. Christopher’s Hospital for Children (SCHC) from 2006-2018 that were found to have EPP. Pituitary hormone function was evaluated in the majority of the patient population. Results: Of the 26 patients with EPP, [16 males (M) and 10 females (F)], mean chronologic age was 5.98+5.18 yrs, only 20 patients had an endocrine evaluation at SCHC. Of the 20 children, 14 had CPHD and 4 had IGHD. Patients were classified into 3 groups (upper, middle & lower) according to EPP location along the pituitary stalk. Of the 21 patients with upper EPP, 17 had pituitary dysfunction (14 with CPHD, 3 with IGHD). Of the 4 children with middle EPP, only 1 had pituitary dysfunction which was IGHD. One patient had lower EPP with hyperprolactinemia. Diabetes insipidus was not identified in any of the children. Conclusion: Our study supports previous reports that CPHD and IGHD are frequent in patients with EPP. Similarly, our data further demonstrate that no cases of diabetes insipidus have been reported in children with EPP. In our study, EPP is most commonly located along the upper third of pituitary stalk at the median eminence level, with a higher prevalence of CPHD and IGHD, a finding similar to prior studies. No CPHD was reported in middle/lower but IGHD was found in the middle EPP group.