ESPE Abstracts

Background and objective: Children with Thickened pituitary stalk (TPS) and/or Idiopathic central diabetes insipidus (ICDI) present to different (endocrine, oncology, and ophthalmology) specialists. Their rarity, absence of agreed radiological criteria or consensus guidance, make their management problematic. Biopsy is too dangerous and cases may remain undiagnosed or evolve over decades. We aimed: i) to longitudinally characterize a large childhood cohort presenting with TPS and/or ICDI ii) to assess radiological, clinical, visual, and endocrine correlates over time.

Method: We searched the terms ‘thickened pituitary stalk’ or ‘idiopathic diabetes insipidus’ in electronic radiology and clinical document libraries at our centre over the last 30 years. 63 retrospective longitudinal data sets in patients with either TPS and/or ICDI were collected and MRI scans reviewed. In nine patients the diagnosis was clear at presentation. Within the remaining 54 occult cases: ten had TPS, 18 ICDI, and 26 TPS+ICDI.

Results: Patients with TPS were older (TPS: 9.8±4.9 years) at presentation than those with ICDI (5.5±4.4 years) and TPS+ICDI (6.2±3.4 years) (P<0.04). TPS+ICDI patients were more likely (38.5%) than ICDI (5.6%) and TPS (none) to have histiocytosis. Tumours were identified in 26.9% TPS+ICDI and 27.9% ICDI, 1.0±1.4 and 1.9±2.4 years later respectively, but not in TPS. 80% TPS cases remained unexplained (vs 61.1% ICDI and 34.6% TPS+ICDI) at a shorter follow-up (2.5 vs 5.2 and 5.8 years). Multiple anterior pituitary deficits evolved with time across groups (GHd, 45–58%, TSHd 19–30%, ACTHd 13–21%, and GnRHd 7–17%) but visual deficits, present in 8–23% at presentation, increased only in TPS+ICDI (7.6–34.6%).

Conclusion: Longitudinal endocrine assessment of all patients with TPS and ICDI is important. ICDI is a negative prognostic factor for malignant disease, whilst the combination with TPS is more often associated with histiocytosis. TPS alone is unlikely to lead to malignancy but should be prioritized for endocrine follow-up.