Incidental brain lesions in children: to treat or not to treat?

Central nervous system (CNS) lesions that are discovered incidentally when imaging children for problems that were unrelated to the detected lesion pose a dilemma to physicians. Because there are few data on the outcome of such cases, we retrospectively reviewed the clinical course of a group of children followed at our institution with brain lesions found incidentally on neuro-imaging. A database of all children with brain lesions followed at the University of Rochester medical center from 2000 to 2010 was reviewed. Data were obtained regarding presentation, magnetic resonance imaging (MRI) features, treatment, progression-free survival, and overall survival of children with brain lesions found incidentally. Of the 244 children with brain lesions seen over this time period, 21 (8.6%) were found to have incidentally discovered brain lesions. Of these 21 children, 12 (57%) underwent surgical resection of their brain lesions. Ten patients (48%) had symptoms considered to be unassociated with the detected lesion. Lesions were found in the cerebellum (n = 7, 33%), midline (n = 5, 24%), and cerebrum (n = 9, 43%). All lesions were ≤5 cm in diameter. Eight patients (38%) had surgery at presentation, one because of imaging features suspicious for a posterior fossae ependymoma, and the seven others because of location in the posterior fossae or brain stem. Of the remaining 13 patients, five had progression of disease on serial MRI scans: four underwent surgery and the fifth was monitored and remained stable after the initial progression stabilized. Nine of the ten patients (90%) with posterior fossae lesions underwent surgery, while only three of 11 with supratentorial lesions underwent surgery (27%) (P = 0.006). The progression free survival was 94% at 12 months (95% CI 65-99%) and 71% at 24 months (95% CI 39-88%). At a median follow-up of 32 months, the overall survival was 100%. Incidentally detected CNS lesions are usually small. The outcome for children with such lesions is excellent. Close monitoring of these patients with serial MRIs may be a safe alternative to immediate biopsy and/or resection for select patients.