Endocrine Abstracts

JOINT3774

Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by increased risk of tumour development and endocrine disorders. Despite the well-established relationship between NF1 and certain endocrinopathies, the prevalence of these disorders in NF1 patients remains unclear, hindering follow-up strategies.

Objective: This study aims to assess the prevalence of endocrinopathies in NF1 patients at our centre.

Methods: Retrospective analysis of NF1 patients observed in the Endocrinology department from 1997 to 2024. Statistical analysis was performed using IBM® SPSS® Statistics.

Results: Of 669 NF1 patients followed at our centre, 255 [141(55.3%) females] were referred to the endocrinology department, 166 of whom during childhood. The mean age at first observation was 10.24±4.51SD years for paediatric and 41.07±14.56SD years for adult patients. The most common pituitary deficiency was growth hormone deficiency (GHD) (9.02%, n = 23), mainly in children (n = 22; mean age at diagnosis 11.21±3.31SD years). Optic pathway gliomas (OPG) were present in 78.26% of these cases (n = 18, P < 0.001), corroborating higher risk in patients with brain tumours. Additionally, 51 patients were diagnosed with short stature, but only 18 of these patients had GHD, suggesting a likely multifactorial aetiology. The prevalence of other pituitary deficiencies was lower: 1.96%(n = 5; 4 with OPG) for hypogonadotropic hypogonadism, 1.18% (n = 3, all with OPG) for secondary adrenal insufficiency. A single case of central hypothyroidism was identified in a 3.67-year-old patient with OPG. The prevalence of precocious puberty was 4.31%(n = 11), 10 of whom had OPG (P < 0.001); 5.49%(n = 14) patients were diagnosed with accelerated puberty, 6 with OPG. Gynecomastia was noted in 8 male patients, 4 were pathologic (1.57%). Thyroid disorders occurred in 16.47% of patients (n=41); 3(1.18%) patients had thyroid carcinomas (2 papillary, 1 medullary), the earliest diagnosed at 36.58 years. Primary hyperparathyroidism was diagnosed in 1.96%(n = 5) patients (mean age: 56.95±10.60). Paragangliomas were found in 3.14% of the patients (n = 8): seven adrenal and one abdominal paraganglioma, incidentally diagnosed. Earliest age at diagnosis was 33.10 years. In addition, 4(1.57%) patients were diagnosed with adrenal adenomas, 1 with adrenal carcinoma and another with congenital adrenal hyperplasia. Gastroenteropancreatic neuroendocrine tumours were detected in 3(1.18%) adults.

Conclusion: NF1 has a prevalence of 1 in 3000. Overall, 17.19% of patients presented with, at least, one endocrine disorder. The diversity of endocrinopathies in NF1, especially in association with OPG, requires regular clinical evaluation and biochemical/imagiological screening. Understanding the prevalence of these disorders is the key to optimizing follow-up and patient care.