Prenatal diagnosis and conservative management of a congenital cavernous sinus infantile hemangioma: illustrative case.

backgroundInfantile hemangiomas (IHs) are the most common benign vascular tumors of infancy, although intracranial IHs remain exceedingly rare. Diagnosis is typically postnatal, with some cases requiring medical or surgical intervention. Here, the authors report the first case of a congenital cavernous sinus IH diagnosed via prenatal imaging and managed conservatively with successful spontaneous regression. OBSERVATIONS: A 28-year-old female underwent routine fetal ultrasound at 32 weeks' gestation, revealing a 1.8-cm perithalamic lesion. Fetal MRI at 33 weeks confirmed an extra-axial mass in the right middle fossa with a dural attachment. Postnatal MRI on day 1 of life demonstrated imaging features consistent with an IH. Given the neonate's asymptomatic status, conservative management was pursued. Serial MRI at 10 weeks and 6 months showed progressive lesion regression, with near-complete resolution. The infant remained asymptomatic with normal neurodevelopmental progress. LESSONS: This case highlights the potential for spontaneous regression of congenital intracranial IHs diagnosed prenatally. Despite the risk of bleeding, conservative management with close clinical and radiological follow-up may be a viable option in select asymptomatic cases, particularly in the neonatal period when surgical risks are significant. https://thejns.org/doi/10.3171/CASE25274.