Pituitary Stalk Interruption Syndrome

Pituitary stalk interruption syndrome (PSIS) is a rare, congenital disorder characterized by a triad of a thin or interrupted pituitary stalk, aplasia or hypoplasia of the anterior pituitary, and absent or ectopic posterior pituitary (EPP) seen on magnetic resonance imaging (MRI). It can either present at birth or later in life. PSIS is very heterogeneous with respect to its hormonal, clinical, and radiological presentation. The patient described is an 18-year-old male who presented with complaints of short stature and underdeveloped secondary sexual characteristics with weight and height of less than three percentiles for his age. The secondary sexual characteristics were consistent with Tanner Stage II. Some of the pituitary hormones were also deficient. Wrist X-ray was compatible with a bone age of a seven- to eight-year-old. MRI confirmed the diagnosis of PSIS (pituitary stalk interruption syndrome).