MRI Features in Children with Pituitary Stalk Interruption Syndrome: Associations with Hormonal Phenotype and Intracranial Anomalies.

Abstract

Rationale and objectives: Pituitary stalk interruption syndrome (PSIS) is a rare congenital disorder with variable endocrine and magnetic resonance imaging (MRI) phenotypes, and the relationship between MRI features, hormonal phenotype, and associated intracranial anomalies remains incompletely understood. This study evaluated MRI features associated with hormonal phenotype and intracranial anomalies in pediatric PSIS.

Materials and methods: This retrospective study included 51 pediatric patients with biochemically confirmed pituitary hormone deficiency and MRI findings of PSIS. Pituitary stalk morphology was classified as absent, interrupted, or thin. Anterior pituitary volume was assessed by two- and three-dimensional methods, and two-dimensional volumes were converted to age- and sex-specific z-scores. We analyzed associations between MRI findings, hormonal phenotype, and intracranial anomalies using univariable and multivariable methods.

Results: Growth hormone deficiency was present in 49 patients (96.1%) and multiple pituitary hormone deficiency (MPHD) in 23 (45.1%). Intracranial anomalies were detected in 31 patients (60.8%), most commonly corpus callosum dysgenesis. MPHD was more frequent with an absent stalk (18/23, 78.3%) than with an interrupted (3/8, 37.5%) or thin stalk (2/20, 10.0%) (p < 0.001), and intracranial anomalies followed the same gradient (p < 0.001). After adjustment for age and intracranial anomalies, absent or interrupted stalk morphology remained independently associated with MPHD (odds ratio 16.8, 95% confidence interval 2.2-130.1; p = 0.007), driven primarily by the absent-stalk group. Neither two- nor three-dimensional anterior pituitary volume nor volume z-scores differed significantly between the isolated deficiency and MPHD groups; sella morphology also showed no significant association with hormonal phenotype.

Conclusion: Pituitary stalk morphology, particularly an absent stalk, showed the strongest association with hormonal phenotype and intracranial anomalies in pediatric PSIS.