Arginine Vasopressin Deficiency in Children with Craniopharyngioma and Cerebral Germ Cell Tumour: Two Sides of the Same Coin - Clinical and Radiological Features.

introductionPaediatric brain tumours in the sellar-suprasellar region are often associated with arginine vasopressin peptide deficiency (AVPD), either at diagnosis caused by the tumour itself or during follow-up as a consequence of treatments. The purpose of this research was to retrospectively describe the neuroradiological characteristics and the timing of AVPD development in a cohort of paediatric patients with craniopharyngioma (CP) or germ cell tumours (GCTs).

methodsWe evaluated brain MRI at tumour diagnosis and at the onset of AVPD, as well as recorded clinical, endocrinological, and histopathological data, treatments, and outcome.

resultsSeventy-two patients with AVPD were included: 46 CPs (M:F = 25:21) and 26 GCTs (M:F = 18:8). CPs were suprasellar (63%), sellar (4%), or both (33%). GCTs were suprasellar (65%), pineal (24%), or bifocal (11%). No statistically significant differences were noted in tumour size between CP and GCT. Posterior pituitary bright spot absence was reported at diagnosis or at follow-up (as surgery consequence) in all patients with AVPD, indicating that the absence of hyper-intensity is a cardinal feature of AVPD. When measurable, pituitary stalk was thickened in most GCT patients (61.5%). At AVPD diagnosis in GCT, the mean age was 11.9 years; 18 (69%) patients had AVPD at the time of tumour diagnosis, 5 (19.3%) before the diagnosis with a latency of 24.4 months (range 4-48), and 3 (11.5%) during follow-up (mean 24 months, range 4-60) due to tumour recurrence. GCT patients presented with severe endocrinological manifestations (18/26), headache and vomiting (10/26), visual impairment (5/26), and behavioural changes with fatigue (1/26). In CP, the mean age at AVPD diagnosis was 10.3 years; 7 (15.2%) patients had AVPD at time of tumour diagnosis, 37 (80.5%) developed it shortly after neurosurgery, and 2 patients (4.3%) after 2 and 4 months from surgery, respectively. Clinically, headache and visual abnormalities were the most frequent clinical symptoms at diagnosis of CP (39/46, 84.8%), with hydrocephalus (16/46, 35%) and displacement of optic chiasm (29/46, 63%) at the initial MRI. While the vast majority of CP patients (93%) received only surgery, all GCT patients received radiation therapy in addition to or instead of surgery.

conclusionAn early differential diagnosis in children with AVPD and brain tumours is supported by a good understanding of the clinical features and imaging findings. Expert follow-up is necessary.