The challenging diagnosis of pituitary stalk interruptionsyndrome: a case report

Abstract

Pituitary stalk interruption syndrome (PSIS) is a rare congenital abnormality affecting thehypothalamic pituitary complex. It is characterized by a peculiar radiological triad which includes thin or interruptedpituitary stalk, hypoplasia or aplasia of the adenohypophysis and absent or ectopic neurohypophysis seen on magnetic resonance imaging (MRI). Patients affected by PSIS may show a wide range of clinical manifestations depending on the variable involvement of pituitary specialized cells, ranging from isolated to multiple pituitary hormone deficiency.  The exact aetiology of PSIS is still uncertain, even if genetic causes arelikely to be involved in some cases, especially mutations in genes implicated in pituitary and neuronal development. Prognosis may vary according to several factors, the most relevant of which is diagnostical-timing, being strictly related to the start of hormonal replacement therapy.This report describes an emblematic PSIS case diagnosed in a 15-year-old girl with primary amenorrhoea and short stature. Her past medical history was not significant. Accurate diagnostic investigation including bone age examination, basal hormonal evaluation and growth hormone stimulation dynamic tests were performed, revealingcombined pituitary hormone deficiency (CPHD). MRI findings confirmed a picture of PSIS. The case highlights the importance of accurate history taking and careful monitoring of growth and pubertal development, which is crucial to avoid diagnostic delay and to allow promptly hormonal replacement therapy.