RESUMO
We report two cases of rapidly involuting congenital hemangioma (RICH) of the skull diagnosed in the third trimester of gestation, and also present a brief review of the literature. In both of our cases ultrasound examination showed a soft tissue vascular mass of the skull with a specific sonographic finding: a thin hyperechogenic line over the lesion and continuous with the calvaria, suggesting a subperiosteal origin and possibly accounting for a mass effect on the underlying skull. This was slight in one case and marked in the other (and associated with involvement of the calvaria). On prenatal T2-weighted magnetic resonance imaging, the signal of each of the lesions was less marked than the hypersignal encountered in the postnatal period. Postnatal clinical and radiological follow-up over the first few months after delivery confirmed the diagnosis of RICH in each case by demonstrating a significant decrease in the size of the tumor and regression of the vascular component, with complete involution of the lesion within a year.