The authors report two cases of cavernous malformation characterized b
y a multilobular appearance on magnetic resonance images. At surgery,
the malformations consisted of several nests of angiomatous components
that were separated by intervening brain tissue and connected with ea
ch other by tiny vessels. This basic configuration seems to explain th
e unexpected postoperative recurrence of cavernous malformations and/o
r rebleeding from the residual lesions.