Spontaneous complete regression of congenital brain tumors - a systematic literature review and case report.

PURPOSE: The study aimed to review the available literature on spontaneous complete regression of congenital brain tumors and report an institutional case with a posterior fossa tumor that involuted at the age of 3 months. METHODS: A systematic review was conducted in accordance with PRISMA guidelines. The study protocol was registered with INPLASY. A systematic review of the articles published from inception to 5 April 2026 in Web of Science, Scopus, PubMed (MEDLINE), and Embase was conducted. Six eligible case reports were identified and included in the analysis. RESULTS: Initial clinical presentation varied, with neurological deficits observed in 2/7 patients, signs of intracranial hypertension in 4/7 patients, and no neurological symptoms in one neonate. Tumors were most commonly located within deep brain structures (3/7), followed by cortical regions (2/7) and extracerebral locations (1/7). Histopathological grading revealed high-grade tumors in 3/7 patients and low-grade tumors in 2/7 individuals. Tumor resection was not pursued because of risky tumor topography (2/7), presumed benign tumor biology with a wait-and-see strategy (1/7), or parental decision to pursue hospice care (1/7). In three individuals, tumor surgery had been initially planned after gaining a greater body weight. Complete spontaneous regression was achieved between 3 and 33 months of age. CONCLUSION: Spontaneous complete regression of congenital brain tumors is a rare and incompletely understood phenomenon. Our study highlights the heterogeneity of histopathological findings, lesion localization, and the subtle clinical presentation in this age group.