Endocrine Abstracts

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant disorder, characterized by the predisposition to the development of multiple endocrine tumors mainly affecting parathyroids, gastroenteropancreatic neuroendocrine tissues (GEP-NET) and pituitary (PT). Mutations of the MEN1 gene are responsible for the disease and may be inherited from one of the parents or more rarely can occur de novo. In children and adolescence there is a paucity of clinical studies. The aim of this study was to describe our experience in MEN1 children and adolescents aged ≤21 years collected and followed-up at our outpatient clinic from 1993 to 2023. A total of 20 patients (10 females and 10 males), affected by familial MEN1 were collected. Mean age at first MEN1 diagnosis was 17±3 years (range 8-21). All patients carried MEN1 mutation. Sixteen patients (80%) developed an endocrine tumor ≤21 years (mean 16±3 years, range: 8–21) and 5 were healthy carriers. Seventy percent of patients had primary hyperparathyroidism (PHPT), (mean 17±2.7 years, range 12-21), 35% a GEP-NET tumor (mean 19.0±1.5 years, range 17-21) and 35% a PT tumor (mean 17±4.5 years, range 8-21). Patients with PHPT at diagnosis had a mean albumin-corrected serum calcium of 11.1±0.74 mg/dl and PTH (evaluated as fold increase of the upper limit of reference range) of 1.37. At diagnosis, 9/15 subjects had at least one target organ involvement of PHPT (hypercalciuria in 6; nephrolithiasis in 3, reduced bone mineral density in 6: mean lumbar Z-score -2.4; femoral neck -2.4; total femur -2.3; 1/3 distal radius -2.9 DS). During the follow up (mean 10 years), one-third (27 %) of patients underwent parathyroid surgery, with a mean age of 20 years (range 16–25); four had the removal of GEP-NET tumor between 21 and 32 years, with histological diagnosis of insulinoma in one, gastrinoma in one and non-functioning in two. No patient had metastases. All except one patient with PT tumors underwent pituitary surgery. The only symptomatic patient had a PRL-microadenoma, treated with cabergoline. Our study suggests that morbidity from MEN1-related manifestations occurred during childhood and adolescence in 80% of patients, being PHPT the most frequent. These findings have implications for the counseling of young MEN1 patients and their families and underscore the importance of initiating surveillance screening early in childhood. Furthermore, it is important to carry out periodic monitoring of all MEN-related endocrine pathologies in order to define the most appropriate therapeutic procedure.