Mouallem, Rayane El

Abstract Purpose Sellar and parasellar lesions in children have heterogeneous clinical presentations and variable endocrine morbidity. Population-based data describing endocrine outcomes across lesion types and management strategies remain limited. Methods We conducted a retrospective, population-based cohort study of patients aged 18 years or younger who were diagnosed with sellar or parasellar lesions between 1976 and 2021 in a multicounty region. Clinical presentation, lesion characteristics, management, and endocrine outcomes were abstracted from medical records. Associations were evaluated by lesion type, lesion size (< 10 mm vs. ≥10 mm), and management approach. Results Among 104 patients, endocrine abnormalities at diagnosis differed by lesion type (p = 0.0004) and were most frequent among patients with pituitary adenomas. Endocrine dysfunction at presentation was more common with lesions ≥ 10 mm than with lesions < 10 mm (74.2% vs. 49.2%; p = 0.0217). Post-treatment endocrine abnormalities were also more common with lesions ≥ 10 mm (64.5% vs. 13.1%; p < 0.0001). Surgical treatment was associated with a higher prevalence of post-treatment endocrinopathy, although this association may reflect lesion size, diagnosis, and treatment selection. Conclusions Endocrine morbidity was common in this population-based pediatric cohort and was associated with lesion type and size. Clinically relevant endocrine abnormalities also occurred in smaller lesions, supporting endocrine evaluation regardless of lesion size and the need for longitudinal surveillance in patients with sellar and parasellar disease.

Abstract Disclosure: R. El Mouallem: None. T. McKenzie: None. A.N. Lteif: None. Background- Pancreatic neuroendocrine tumors (PNETs) are rare, but their incidence is rising. Ethanol ablation is increasingly used in adult patients with insulinomas or small nonfunctional PNETs, particularly in patients who are ineligible for surgical resection. Ethanol ablation of a PNET has not been previously reported in the pediatric population. Clinical Case- A 12-year-old female with known multiple endocrine neoplasia type 1 (MEN1) and multifocal PNETs presented for evaluation of a 1.3 cm nonfunctional, Dotatate avid pancreatic uncinate lesion. A CT angiogram of the pancreas revealed an arterially enhancing 1.3 cm nodule, which measured 8 mm one year prior. There was no evidence of metastatic disease. Given the increasing size of the lesion and young age of the patient, operative intervention was pursued. Due to the depth of the lesion and its proximity to the pancreatic duct during operative pancreas ultrasonography, surgical enucleation was deemed non-feasible. During the procedure, 7 additional subcentimeter pancreatic lesions concerning for PNETs were identified in the pancreatic body, tail, head and neck-body junction. Ultrasound guided ethanol ablation of the primary lesion was performed. Follow-up imaging demonstrated a promising response. 7 months post ablation, a Dotatate PET CT scan showed persistent focal uptake in the region of the ablated nodule. However, by 9 months, MRI abdomen revealed a decrease in the size of the lesion, now measuring 6 mm, with stable Dotatate uptake. By 19 months post ethanol ablation, the previously hyper-enhancing lesion was no longer visible on MRI, demonstrating complete structural resolution. Conclusion- This case demonstrates that ethanol ablation is a promising treatment option for PNETs in the pediatric population. Given the complexities of surgical resection in children, particularly for deep or anatomically challenging lesions, ethanol ablation offers a potentially less morbid alternative with encouraging outcomes. Further research may establish this approach as a viable option for select pediatric patients. Presentation: Sunday, July 13, 2025