Endocrine Abstracts

Introduction: Pituitary stalk interruption syndrome is a rare disorder characterized by a specific tirade: an absent or hypoplastic anterior pituitary gland, thin or absent infundibulum, and ectopic posterior pituitary location. This syndrome has been described in association with other somatic abnormalities and recently a polygenic etiology has been suggested. Herein, we report a case of type 1 diabetic patient, explored for short stature, revealing a pituitary stalk interruption syndrome.

Case presentation: We report the case of an 8-year-old patient, with a medical history of type 1 diabetes since the age of two. During his follow up, stature delay has been noticed but initially put on the account of diabetes. At the age of eight, he consulted our endocrinology department. Physical examination showed a height of 110 cm which was below the second percentile for chronological age, and weight was 23 kg which was at the third percentile. Bone age was five years according to the Greulich and Pyle method. Biological analysis revealed an HbA1c level of 7,5%. First line investigation, including complete blood count, creatinine and liver enzyme was normal. Antitissue transglutaminase, anti-endomysium, and anti-gliadin antibodies were negative. The hormonal investigation showed a normal thyroid function test (TSH level of 1.35 mIU/l and free thyroxine of 10.9 pmol/l). The diagnosis of corticotropic insufficiency was confirmed by a low baseline plasma cortisol level (168 nmol/l) unstimulated by Insulin-induced hypoglycemia test and low adrenocorticotropin hormone (ACTH) level. IGF1 levels were 82 ng/mL which was normal for age. The diagnosis of GH deficiency was retained based on no GH response to two stimulation tests: Insulin-induced hypoglycemia and clonidine tests. Pituitary MRI showed the typical triad of pituitary stalk interruption syndrome. The patient was treated with hydrocortisone and recombinant GH replacement therapy with good evolution of stature.

Conclusion: Pituitary stalk interruption syndrome should be kept in mind while investigating a child with short stature, even if patient history suggests other etiologies. The pathophysiology of this syndrome is not yet fully understood, but it has been described in association with several diseases and appears to be polygenic.