Spinal Cord UBOs in NF1 Pediatric Patients: Single Institution Experience

Abstract

Introduction: Neurofibromatosis type 1 (NF1) is a neurocutaneous disease that shows specific clinical characteristics and imaging. Being a predisposition syndrome to diferent tpes of tumors, neurofibromas and glioma of the optic pathway being the most common lesions. It is essential to know the typical, non-oncological lesions that can be present and diagnosed through neuroimaging, so that they are not missdiagnosed and treated incorrectly. Within these lesion we foun UBOs (Unidentified bright objects), located on white matter areas in the parenchyma, but little taken into account at spinal cord level. Aims: To describe the prevalence of UBOs located in the spinal cord, in patients with NF1 during childhood, based on data obtained at our institution. Materials and methods: Retrospective, observational and descriptive study of patients between 2 and 21 years old with NF1 diagnosis, evaluated during 2009 to 2023 time period, who had whole brain and spinal cord MRI (n=32). The presence of UBOs was evaluated. We refer to spinal UBO as single or multiple lesions located in the cord, hyperintense on T2/STIR sequences and isointense on T1, without gadolinium enhancement or mass effect. Results: Male patient 58.3%, with an average age of 13.1 years. Twenty seven patients (79%) had brain UBOs and 9 (26.4%) Spinal cord UBOs. Of the latter, 44.4% presented a single spinal cord lesion, the rest had more than one. The most comon location was the subaxial cervical (C3-T1) area, followed by the cervical superior (C1-C2) area, dorsal with 2 lesions and conus medullaris in only one case. In all of them, hypersignal was found in T2 sequence and isointense signal in T1; no case showed enhancement with intravenous contrast or mass effect. There was coexistence of brain UBOs in all our patients. None of the patients presented clinical manifestations associated with these lesions. Conclusion: There is little literature regarding the existence of spinal UBOs. It is important to recognize the existence and diagnostic imaging characteristics of these in order to avoid diagnostic and therapeutic errors regarding the presence of spinal cord lesion in NF1 patients.