Pituitary Magnetic Resonance Imaging as a Prognostic Factor of Pituitary Insufficiency-The Follow-Up Analysis of a Cohort of Children With Pituitary Stalk Interruption Syndrome.

BACKGROUND

Patients diagnosed with pituitary stalk interruption syndrome (PSIS) exhibit heterogeneous endocrinological and radiological presentations.

OBJECTIVE

The aim of this study was to assess the correlation between MRI features in children with PSIS and their pituitary hormonal profile, and answer the question whether pituitary MRI can serve as a prognostic factor of pituitary insufficiency.

DESIGN AND PATIENTS: The study included 50 children diagnosed with PSIS. Hormonal data were collected at the first and most recent visits; with a median follow-up of 5.9 years. Data collected before 2016 were retrospective; thereafter, prospective.

RESULTS

At initial diagnosis, 32 patients (64%) presented with isolated pituitary hormone deficiencies. During follow-up, 15 of them (47%) developed additional deficits, increasing the prevalence of combined pituitary hormone deficiency (CPHD) from 16 (32%) to 31 patients (62%). In the remaining 17 patients (34%), only the initial isolated growth hormone deficiency (GHD) diagnosis persisted. Progression to CPHD occurred in 87.5% of patients with stalk agenesis compared to 33.3% with stalk hypoplasia (p = 0.013). All cases of arginine vasopressin deficiency (AVPD) were observed exclusively in patients with the absence of the posterior pituitary (Fisher's exact test, p < 0.000001; odds ratio = 0, with 95% CI: 0-0.04). Furthermore, the presence of optic nerve hypoplasia (ONH) was strongly associated with the development of CPHD.

CONCLUSIONS

Children with PSIS require repeated reassessment of pituitary function if CPHD is not present at the initial evaluation, as progression to complete pituitary insufficiency may occur over time. The absence of the pituitary stalk may serve as a sensitive marker of CPHD, whereas the absence of the posterior pituitary appears to predispose patients to AVPD. Additionally, the coexistence of ONH and PSIS may be associated with greater severity of anterior pituitary hormonal dysfunction. Patients who do not develop CPHD typically present with growth failure as the main manifestation, along with pituitary stalk hypoplasia and partial GHD.