The neurovascular triad: mixed cavernous, capillary, and venous malformations of the brainstem.
OBJECTIVE
The four types of cerebrovascular malformations may sometimes be combined and more often occur in pairs; triads are exceptional. The authors present six patients with the clinicoradiographic profile of mixed vascular malformations of the brainstem, including cavernous malformation (CM), capillary telangiectasia, and developmental venous anomaly (DVA).


METHODS
Five patients (one of whom was a child) suffered from hemorrhage, suggesting that this complex association has a high bleeding potential. Progressive growth, rebleeding, and de novo occurrence of the associated CM were documented in three cases. Magnetic resonance imaging of the brain was obtained in all patients by using one or more of the following modalities: T1-weighted sequences before and after gadolinium administration; T2-weighted sequences; T2-weighted fluid attenuated Inversion recovery; T1-weighted fast spin echo; and diffusion weighted, diffusion tensor, and perfusion imaging in three cases.


RESULTS
Three patients were surgically treated with the intention of excising the hemorrhagic lesion, but only two patients had their malformations successfully removed. In the third case, diffuse pontine telangiectasia precluded the safe excision of the CM. Histological examination demonstrated a blended pathological milieu characterized by coalescent telangiectasia and venules associated with loculated endothelial chambers resembling an immature or de novo CM. Three patients were treated conservatively; recurrent minor hemorrhage occurred in one case. The authors found these malformations to be arranged in two basic relationships: CM inside the telangiectasia and CM in the radicles of the DVA. Stenosis of the main venous collector and dilation of the medullary veins were important findings.


CONCLUSIONS
The pathogenesis of this malformation may be referred to a developmental deviance of the brainstem capillary-venous network associated with transitional vessels and loculated endothelial vascular spaces related to genetic and acquired origins, probably in a restrictive venous outflow milieu.
Pozzati
Eugenio
E
Department of Neurosurgery, Sections of Neuroradiology and Pathology, Bellaria Hospital, Bologna, Italy. eugenio.pozzati@ausl.bo.it
Marliani
Anna Federica
AF
Zucchelli
Mino
M
Foschini
Maria Pia
MP
Dall'Olio
Massimo
M
Lanzino
Giuseppe
G
D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D001933:Brain Stem / Q000098:blood supply*; D002196:Capillaries / Q000002:abnormalities; D002426:Cavernous Sinus / Q000002:abnormalities; D020785:Central Nervous System Vascular Malformations / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D002543:Cerebral Hemorrhage / Q000209:etiology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures; D012008:Recurrence; D014680:Veins / Q000002:abnormalities