Cranial Cavernous Malformations

Abstract

Cavernous malformations (CMs), also known as cavernous angiomas or cavernomas, are low-flow vascular malformations of the brain and spinal cord that consist of clusters of dilated sinusoidal channels lined with endothelial cells that do not exhibit intervening tight junctions. The involved blood vessels lack muscular and elastic layers, and blood at various stages of thrombosis and organization often fills the thin-walled vascular caverns. CMs are grossly distinct from adjacent brain and have a lobulated appearance sometimes likened to a mulberry, with a characteristic dark red or purple color. Hemosiderin and gliosis often surround CMs of the brain and spinal cord; no neural tissue is present inside the lesion. Except for developmental venous anomalies (DVAs) present in ≈33% of CMs,1 no abnormal vascularity is typically seen on digital subtraction angiography, leading CMs to be termed cryptic or occult vascular malformations (Figure 1). Multiple small hemorrhage events lead to a pathognomonic popcorn appearance on magnetic resonance (MR) imaging because of hemosiderin staining from blood products of various ages. Calcifications may be present on computed tomographic imaging (Figure 2).Figure 1. A 48-year-old woman presented with headaches. A, Magnetic resonance imaging of the brain with T2-weighted imaging demonstrated a 1.1-cm lesion in the cerebellar vermis with mixed signal intensity. B–D, Susceptibility-weighted imaging demonstrated hemosiderin within the lesion’s core and a developmental venous anomaly associated with the cavernous malformation (arrowheads).Figure 2. A 28-year-old woman presented with partial seizures without secondary generalization. A, Noncontrast computed tomography of the head demonstrated a 1.4-cm right posterior cingulate hyperdensity, with evidence of mild hemorrhage and calcification. Magnetic resonance imaging of the brain demonstrated the cavernous malformation to have a core of mixed signal intensity, heterogeneous enhancement, and a rim of hemosiderin consistent with a cavernous malformation, as evidenced on (B) susceptibility-weighted imaging, (C) T2-weighted …