Radiological features of childhood giant cavernous malformations

Giant cavernous malformations (GCM) are very large, low-flow vascular malformations, which usually have atypical imaging features and are commonly misdiagnosed preoperatively as neoplasms or vascular malformations. These lesions have mostly been reported in children. As cavernomas show different features in children compared to adults, we evaluated the imaging features of pediatric GCMs in order to help in the preoperative diagnosis of these malformations.

Brain MR studies of nine children (mean age of 4 years; 8 months-9 years) with biopsy-proven GCM were retrospectively evaluated. We defined GCMs as cavernomas of ≥4 cm. Lesions were evaluated regarding their size, location, signal characteristics, general appearance (uni/multilocular) as well as regarding the presence of mass effect, edema, and fluid-fluid levels and were classified according to the Mottolese classification of pediatric cavernomas.

Lesion locations were parietal (n = 5), frontal (n = 2), temporal, and intraventricular. Seven lesions were in the periventricular region (with five in the periatrial region). Six patients had T1 hyperintense multilobulated lesions with "bubbles of blood" appearance and three patients had heterogeneous lesions with reticular core. All lesions had mass effect, edema (marked in four cases), and peripheral hemosiderin rim. Fluid-fluid levels were also common (n = 7). Most of our lesions (six of nine) were classified as type IIIA, two as type IIIC, and one as type IA.

In children, a GCM should be considered in case of very large hemorrhagic intra-axial mass with "bubbles of blood" multicystic appearance, surrounding hemosiderin ring, fluid-fluid levels, and accompanying edema-mass effect, especially in the periatrial location.