2024 Volume 49 Issue 4 Pages 147-153
Background: There are no sufficient guidelines to determine the surgical indications for asymptomatic lesions of radiologically suspected low-grade glioma. When the patient is a child, it is sometimes difficult to propose a treatment plan due to the patient’s difficulty in making decisions and the influence of parental concerns. The clinical and imaging biomarkers to estimate the clinical course of the lesions would have high clinical value. We investigated the natural course of asymptomatic lesions of radiologically suspected low-grade glioma.
Materials and Methods: This retrospective study was approved by our institutional review board. In all cases, brain tumors were diagnosed incidentally or found in a medical checkup. Lesions of radiologically suspected low-grade glioma were confirmed by subsequent MR examinations. Patients who chose a follow-up policy until the tumor increased in size and/or became symptomatic were enrolled in this study. We excluded patients with contrast enhanced lesions and insufficient follow-up periods of less than 3 years. Patients with an increase in lesion size within 3 years and who were diagnosed with glioma based on the examination of surgical specimens were included in this study, regardless of whether a tumor or non-neoplastic disease was initially suspected.
Results: Twenty-nine patients were included in this study. The lesion locations were as follows: frontal lobe (n＝13), parietal lobe (n＝3), insular gyrus (n＝3), thalamus (n＝3), cerebellum (n＝4), corpus callosum (n＝1), and the midbrain (n＝2). During the follow-up period, eight patients showed no significant change, four showed a decrease in lesion size, and 17 showed an increase in lesion size. Among the 17 patients, 14 were confirmed to have gliomas after surgical resection. We divided the patients into two groups: patients of <18 years of age and patients of ≥18 years of age. A decrease in the tumor size was only observed in the younger age group; the difference was statistically significant (P<0.0001, Fisher’s exact test). We further analyzed the T2-FLAIR mismatch sign and found that its sensitivity and specificity for the diagnosis of astrocytoma were not high in young patients or for incidental lesions.
Conclusion: Considering that asymptomatic non-contrast-enhanced tumors in patients younger than 18 years might not enlarge, careful observation without surgical intervention proved to be a valid option. On the other hand, the risk of these lesions increasing in size in patients who are 18 years and older should be recognized. Careful follow-up is necessary to avoid missing the opportunity to provide appropriate treatment.
