Pituitary stalk interruption syndrome.

A 5-year-old boy presented at the department of Pediatrics because of parental concerns about his delayed growth which had been slowing since the age of 2.5 years. The patient had no significant familial, perinatal or past medical history. At clinical examination, no abnormalities were present. His stature was below the 5th percentile. Laboratory investigations showed normal serum values of TSH, FT4 and prolactin, but an abnormally low IGF-1 concentration. Bone age (Gruelich and Pyle) was 3 years and 6 months, more than one year below his chronological age. MRI of the brain was performed to rule out a hypothalamichypophyseal lesion (Fig. A-D). Midsagittal T1-weighted MR imaging revealed a small sella with a hypoplastic anterior pituitary gland (dotted arrow). The pituitary stalk was extremely hypoplastic and barely perceptible (dashed arrow). An ectopic posterior pituitary gland (solid arrow) was observed as an area of T1 high signal intensity at the median eminence in the floor of the third ventricle between the right and left optic tract (small arrows).