Non-neoplastic brain abnormalities on MRI in children and adolescents with neurofibromatosis type 1
R Raininko1, L Thelin, O Eeg-Olofsson
1Department of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala University, Uppsala, Sweden. raili.raininko@radiol.uu.se
Insights
Neurofibromatosis type 1 (NF 1) often presents with non-neoplastic MRI abnormalities in children and adolescents. These T2-high signal lesions are common and may aid in NF 1 diagnosis.
Area of Science:
- Neurology
- Radiology
- Genetics
Background:
- Neurofibromatosis type 1 (NF 1) is a genetic disorder with varied clinical manifestations.
- MRI is crucial for monitoring disease progression and complications in NF 1.
- Distinguishing neoplastic from non-neoplastic lesions in NF 1 can be challenging.
Purpose of the Study:
- To investigate the occurrence, location, and changes over time of non-neoplastic MRI abnormalities in pediatric NF 1 patients.
- To assess the diagnostic significance of these MRI findings in NF 1.
- To evaluate the potential of T2-high signal lesions as a diagnostic criterion for NF 1.
Main Methods:
- Retrospective analysis of 114 MRI examinations from 35 children and adolescents with NF 1.
- Longitudinal follow-up ranging from 3 months to 10 years.
- Detailed assessment of lesion characteristics on T1-weighted, T2-weighted, and proton density-weighted MRI sequences.
Main Results:
- 89% of NF 1 patients exhibited focal high signal intensities on T2-weighted MRI, predominantly in the cerebellum, brain stem, and deep gray matter.
- Lesions showed dynamic changes (new onset, growth, decrease, disappearance) across all age groups, including late adolescence.
- Five expansive lesions were observed in four patients, with four receding spontaneously, complicating differential diagnosis with neoplastic lesions.
Conclusions:
- High T2-signal lesions are highly prevalent in pediatric NF 1 and represent a significant finding.
- The dynamic nature and appearance of these lesions warrant consideration in the diagnostic criteria for NF 1.
- Further research is needed to clarify the differential diagnosis between neoplastic and non-neoplastic lesions in NF 1.
Abstract:
The occurrence, localization and longitudinal course of non-neoplastic MRI abnormalities in children and adolescents with neurofibromatosis type 1 (NF 1) were studied. Thirty-five patients who satisfied the criteria for NF 1 underwent 114 MRI examinations. They were 9 months to 18 years old at their first examination, and 23 were examined more than once (2 - 11 times). The follow-up time varied from 3 months to 10 years (mean 4 years). Thirty-one patients (89%) showed focal high signal intensities on T2-weighted images in the cerebellum, brain stem, deep cerebral gray matter and, less frequently, in the cerebral white matter. Changes were also seen in 80% and 50% of the proton density-weighted and T1-weighted images, respectively. Newly appearing, growing, decreasing and disappearing lesions occurred contemporaneously and in all ages. New lesions still developed in the late teens. Three lesions showed temporary contrast enhancement. Five expansive lesions were found in four individuals without related clinical symptoms. Four of them receded during follow-up. These cases indicate that the differential diagnosis between neoplastic and non-neoplastic lesions is not clear. The results support the view that high T2-signal lesions are so common in NF 1 that they should be included as another criterion for the diagnosis.
