Endocrine Abstracts

Introduction: Pituitary Stalk Interruption Syndrome (PSIS) is a congenital developmental anomaly affecting the pituitary gland. Characterized by a triad of features including a thin or absent pituitary stalk, adenohypophysis hypoplasia, and ectopic neurohypophysis on MRI, PSIS can lead to isolated or combined pituitary hormone deficiency. Symptoms may manifest at various life stages, with 70% of cases identified in childhood due to growth retardation. Notably, some patients exhibit normal growth despite growth hormone deficiency.

Case report: A 7 year old boy presented to endocrinology clinic with concerns of genital hypoplasia and a history of bilateral cryptorchidism. Review of the patient’s birth history demonstrated an uncomplicated full-term gestation with delivery by cesarean section with a birth weight of 3.2 kg. His motor and language development was normal. Family history was negative. Father’s height was 170 cm; mother’s height was 173 cm; midparental height was 178 cm (+0.15 DS). Recurrent hospitalisations for pneumonia with dehydration were noted in the past medical history, but no history of seizures. On physical examination, the patient’s height was 116.5 cm (-1.26 DS), he had no growth records; his weight was 26.3 kg with a body mass index (BMI) of 19.4 kg/m² (at the 96th percentile). He had no signs of thyroid or cortisol deficiency. The sexual maturity rate was Tanner stage I, with a hypoplastic scrotum, a 4.5 cm penile length, covered by suprapubic fat. Laboratory studies demonstrated low free thyroxine (T4) with only slightly above normal thyroid-stimulating hormone (TSH) values. Repeated and extended hormonal analysis demonstrated a pattern of panhypopituitarism with low morning serum cortisol (0.9 µg/dl, normal 5-25), low normal ACTH (12 pg/ml, normal, 7.2-63.3), low freeT4 (0.4 ng/dl, normal 0.65-2.3) with slightly elevated TSH (5.9 µUI/ml, normal 0.5-4.5), normal prolactin, low IGF1 values (18.7 ng/ml and 17.8 ng/ml, -2.81 SDS for Tanner I) and an inhibin B level of 21.7 pg/ml (2.5-10th centile). The diagnosis of GHD (confirmation with stimulation tests) was not extended at that time due to the inability to treat GH as part of the therapeutic program of a patient with a normal height. The bone age was delayed, 3.5 years old, compared to chronological age. MRI confirmed PSIS, revealing hypoplasia of the adenohypophysis, ectopic neurohypophysis, and an absent pituitary stalk

Conclusion: Herein, we report a pediatric obese patient with an unusual presentation and normal growth despite combined pituitary hormone deficiency in the course of pituitary stalk interruption syndrome (PSIS).