This systematic review and case report address the uncommon phenomenon of spontaneous complete regression of congenital brain tumors. The study aimed to synthesize published cases and to present an institutional patient with a posterior fossa tumor that involuted by 3 months of age. The work highlights the clinical heterogeneity and gaps in understanding of tumor involution in the neonatal and infant age groups.
The authors conducted a systematic review in accordance with PRISMA guidelines and registered the review protocol with INPLASY. They searched Web of Science, Scopus, PubMed (MEDLINE), and Embase for articles published from database inception through 5 April 2026. From the search, six eligible case reports were identified and included in the analysis; the institutional case was added to this cohort to provide a total of seven patients for descriptive synthesis.
Across the seven patients (six previously published cases plus the institutional case), the clinical presentations and tumor characteristics were heterogeneous.
Clinical presentation: signs of intracranial hypertension were reported in 4/7 patients, neurological deficits in 2/7, and one neonate had no neurological symptoms at presentation.
Lesion localization: tumors were most frequently located in deep brain structures (3/7), followed by cortical regions (2/7), with one case arising in an extracerebral location.
Histopathology and grading: high-grade tumors were reported in 3/7 patients and low-grade tumors in 2/7 patients. The abstract does not report complete histopathological details for all cases.
Management decisions: immediate tumor resection was withheld for several reasons—risky tumor topography in 2/7 cases, a presumed benign biology with a decision to observe in 1/7, and parental choice to pursue hospice care in 1/7. In three individuals, surgery had been planned but deferred until patients gained greater body weight.
Timing of regression: complete spontaneous regression was documented to occur between 3 and 33 months of age across the cases.
The data show a variable mix of clinical severity, anatomical locations, and tumor grades among infants whose tumors ultimately regressed without resection.
The institutional contribution described a neonate with a posterior fossa tumor that underwent involution at the age of 3 months. The abstract provides this outcome but does not include additional case-level specifics in the summary (for example, detailed imaging findings, histopathological subtype, serial imaging intervals, or supportive care measures). Therefore, those details were not reported in the source abstract.
The review emphasizes that spontaneous complete regression of congenital brain tumors is rare and incompletely understood. The cases demonstrate heterogeneity across several domains:
Histopathological spectrum: both high-grade and low-grade tumors were represented among regressing lesions, indicating regression is not confined to a single tumor grade based on the available reports.
Anatomical diversity: regression occurred in tumors in deep cerebral structures, cortical locations, and extracerebral sites.
Clinical presentation: neonates and infants may present with subtle or nonspecific findings; some present with intracranial hypertension, others with focal deficits, and some may be asymptomatic.
Management pathways prior to regression varied, from planned surgery deferred until clinical stabilization or weight gain, to conservative observation based on presumed benign biology, and in one instance a parental decision for palliative care. The heterogeneity of presentations and management choices limits generalizable conclusions about predictors of involution.
Key limitations reflected in the abstract include the small number of cases available—six case reports in the literature plus the institutional case—and incomplete reporting of some histopathological and management details in the abstract. The mechanisms underlying spontaneous regression were not elucidated in the summary. The authors note that the phenomenon remains poorly understood and underline the need for more detailed case reporting and mechanistic study.
Spontaneous complete regression of congenital brain tumors is an uncommon and poorly characterized event. The reviewed cases show variable tumor grades, locations, and clinical presentations, with regression occurring between 3 and 33 months of age. Clinicians should be aware of this rare possibility, but the available data are insufficient to guide routine changes in management; decisions must remain individualized. The study advocates for improved documentation and reporting of similar cases to better define predictors, mechanisms, and safe management strategies.
The authors obtained consent from the patient's legal guardians for publication of the case. Ethics approval was reported as not applicable, and the authors declared no competing interests. The publication cites PMID 42722758 and DOI 10.1007/s00381-026-07458-8 for reference.