ESPE Abstracts

Background/aims: Pilocytic astrocytomas (PA) are low-grade neoplasms that affect the precortical visual pathway and are most commonly detected in children and adolescents, representing 2–5% of childhood central nervous system (CNS) tumours. Optic gliomas (OPGs) can occur sporadically, or in association with neurofibromatosis type 1 (NF1). We assessed the prevalence of endocrine dysfunction in children with PA and evaluated outcomes between subgroups of PA, including OPGs, non-optic pathway gliomas (non-OPGs) and NF1 related OPGs.

Methods: A retrospective follow-up study of 81 children with PA [OPG (n: 44), NF1 (n: 21), non-OPG (n: 16)] evaluated between 1999 and 2024 was undertaken.

Results: The study included 81 patients (38 female) with PA with a mean age at diagnosis of 7.5+4.8 years. The most common initial complaint was nystagmus (21%), followed by headache (18%) and visual disturbance (12%). Among the 21 NF1 patients, 18 had no symptoms. Endocrinopathies were diagnosed in 40 out of 81 patients (50%). The age at diagnosis and height SDS and BMI SDS at initial endocrinological evaluation were similar across the three groups. The follow-up period was 3.1 years (range: 0.2-14.0 years). We found thyrotropin deficiency in 29.6%; growth hormone (GH) deficiency in 20.9%, ACTH deficiency in 17.2 %, vasopressin deficiency in 14.8 % and obesity with insulin resistance/impaired glucose tolerance 12.3%. Among the 45 patients who had reached post pubertal ages, sex steroid replacement therapy is required for 20% of the patients, and 15 patients (19,7%) were treated for central precocious puberty. The rates of endocrinopathy development were highest in the OPG group (56%), lowest in the NF1 group (38%), and 43% in non-OPG group. The most common endocrinopathy in the NF1 group was precocious puberty (36%), and in the OPG group was hypothyroidism (25%). Among the 30 (16 female) patients who reached final height (FH), 9 patients had GH deficiency but could not be treated due to residual tumour. Their FH-SDS was -2.9±1.3, significantly lower than the GH-sufficient group (-1.6±1.08) (p:0.009). Furthermore, the FH-SDS of the GH-sufficient group were lower than their target height SDS (-0.76±0.92) (p: 0.010).

Conclusion: Our study showed that, regardless to the location, PAs pose high risk for endocrinopathies. Additionally, the FH of the patients are lower than their genetic potential, which is more prounced in GH-deficient group. Our study is the first report FH outcomes in children with PA in the literature.