Ectopic posterior pituitary and stalk abnormality predicts severity and coexisting hormone deficiencies in patients with congenital growth hormone deficiency

Abstract

Certain pituitary imaging abnormalities are a specific indicator of hypopituitarism. The objective of this study is to compare phenotypical features with radiological findings in patients with congenital growth hormone deficiency (GHD). Magnetic Resonance imaging (MRI) was performed in 103 patients [72 with Isolated GHD (IGHD) and 31 with Combined Pituitary Hormone Deficiency (CPHD)]. Images were assessed for the following abnormalities: (1) small/absent anterior pituitary, (2) thin or interrupted pituitary stalk (PSA), and (3) Ectopic posterior pituitary (EPP), and (4) others. Radiological findings were correlated with the clinical and biochemical parameters. MRI abnormalities were observed in 48.6% patients with IGHD, 93.5% with CPHD. Jaundice, hypoxia, hypoglycemia and breech deliveries were more common in EPP/PSA group. EPP/PSA was observed in 87.1% patients with severe GHD (peak GH < 3 μg/L) as compared to 12.9% with mild to moderate GHD (peak GH: 3-10 μg/L). Amongst CPHD, EPP/PSA was present in 80% of subjects with associated hypocortisolism ± hypothyroidism as compared to 18.2% of subjects with hypogonadism. Over a mean follow up period of 4.5 years, 5.4% of subjects with IGHD and abnormal MRI progressed to CPHD while none of those with normal MRI progressed. This study emphasizes a significant clinico-radiological correlation in Asian Indian GHD patients. MRI abnormalities in the hypothalamic pituitary area, especially EPP/PSA are more common in patients with CPHD and severe GHD. Among CPHD, EPP/PSA predicts association with hypothyroidism or hypocortisolism. IGHD with MRI abnormality may evolve into CPHD.