ESPE Abstracts

Introduction: Pituitary stalk interruption syndrome (PSIS) is a congenital anomaly of the pituitary gland responsible for pituitary insufficiency. Its prevalence is unknown but approximately 1000 cases have been reported to date. It is characterized by a triad associating a very thin or interrupted pituitary stalk, an ectopic or absent posterior pituitary gland (EPP) and hypoplasia of the anterior pituitary gland, visible on MRI. Its etiology remains unknown.

Observation: A 4-year-old boy referred to our pediatric endocrinology consultation for short stature. He was born at full term to a non-consanguineous couple. The clinical examination revealed a delay in stature (height - 2.5 Zs). The remainder of the somatic examination was unremarkable. Bone age corresponded to a delay of 2 years. IGF1 levels were low with GH peaking at ?7 ng/ml during stimulation tests. The rest of the hormonal balance was normal. Hypothalamic-pituitary MRI showed an interrupted pituitary stalk with EPP at the level of the third ventricle infundibulum.

Discussion: Our patient presented an isolated anterior pituitary deficiency explaining the clinical picture. The prognosis is good if diagnosis and treatment are early.

Conclusion: PSIS is a rare congenital malformation, responsible for an isolated or multiple anterior pituitary deficiency. MRI is currently the most efficient means of imaging for diagnosis and a prognostic approach. Treatment is based on replacement therapy with deficient hormones. The risk of familial recurrence is less than or equal to 5%.