Endocrine Abstracts

Introduction: Pituitary stalk interruption syndrome (PSIS) is a distinct developmental defect characterized by a thin or absent pituitary stalk, hypoplasia of the adenohypophysis, and ectopic location of the neurohypophysis.

Case report: A 36 years old male patient, full term born by vaginal delivery, with birth asphyxia. Birth weight was 2800 g, length was 51 cm, and no other postnatal events were noticed. Psychomotor milestones were achieved normally. his height remained at −4, −5 S.D. till this thirties. The clinical examination finds particular facial features with central adiposity. MRI hypothalamo hypophysia was performed showing ectopic posterior pituitary located adjacent to the optic chiasm, absent pituitary stalk, and severe anterior pituitary hypoplasia associated to type 1 chiari malformation. Hormonologic assessment showed an hypopituitarism. The patient was put on L-thyroxine, hyrocortisone and testosterone treatment.

Discussion: PSIS is manifested as isolated or combined pituitary hormone deficiencies (CPHDs) with variable timing in the onset of symptoms. The precise etiology of PSIS still remains elusive or incompletely confirmed in most cases. Adverse perinatal events, including breech delivery and hypoxia, were initially proposed as the underlying mechanism affecting the hypothalamic–pituitary axis. Nevertheless, recent findings have uncovered a wide variety of PSIS-associated molecular defects in genes involved in pituitary development. Severe and life-threatening symptomatology is observed in a subset of patients with complete pituitary hormone deficiency during the neonatal period. Nevertheless, most patients are referred later for growth retardation. Prompt and appropriate hormone substitution therapy constitutes the cornerstone of treatment.

Conclusion: PSIS is a developmental defect easily diagnosed by MRI, his diagnosis is often delayed, which often result in a gradual occurrence of multiple pituitary hormones deficiencies, requiring careful follow up of affected patients.

Reference: 1- Acta Endocrinol (Buchar). 2017 Jan-Mar; 13(1): 96–105.