Benign brainstem tumors in children: a retrospective series of 42 patients treated in Lyon

Introduction: Brainstem tumors represent 15% of brain tumors in children. 80% of these tumors are diffuse pontine tumors with a global bad prognosis also with the tailored chemotherapies and radiotherapy. 20% of these tumors are benign and present a good prognosis with only a surgical treatment. Material: All patients admitted with the diagnosis of brainstem tumor in the Pediatric Neurosurgical Department between January 1997 and December 2021 have been considered for this study. We excluded patients with a diagnosis of DIPG or any other malignant histopathology. Results Out of 112 patients with a brainstem tumor, 42 patients had a proved benign histological diagnosis and were included in this study. The average age, at diagnosis, was 8 years old with a median age of 4,7 years. All patients were operated. Forty-eight surgical procedures were realized for the 42 patients: 8 biopsies and 40 direct approaches. Seventeen patients had a surgical treatment for hydrocephalus. Regarding surgical outcome, 8 patients presented motor deficits, six improved while in other two the deficit was unchanged but non impeding the walk. The major clinical complication after surgery was cranial nerve palsy present in 18 patients. Two patients deceased in the early post-operative period and 2 patients for a recurrence after seven and eight years after the diagnosis. 38 patients are alive. Conclusion Benign brainstem tumors can be associated with a favorable evolution, a low growing rate and, when symptomatic, curable with surgery. The surgical resection has to be safe and reasonable to avoid catastrophic complications. The results of surgery are particularly conditioned by the skills and experience of the surgeon.