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

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. 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. 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. 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.