Cavernous hemangioma of the intracranial optic pathways: CT and MRI.

PURPOSE

The purpose of this work was to describe the CT and MR findings in three patients with cavernous hemangioma (CH) of the intracranial optic pathways.

METHOD

CT and MR studies of three patients with CH of the optic chiasm were reviewed. All patients underwent MRI of the chiasmal area, with coronal T2- and T1-weighted studies as well as gadolinium-enhanced coronal and sagittal T1-weighted studies.

RESULTS

The patients (mean age, 40 years) presented with chiasmal apoplexy (two cases) and progressive decrease of visual acuity (one case). In all cases, MRI showed regular enlargement of the optic chiasm, with extension to the optic nerve in one case and to the left optic tract in one case. The chiasmatic dimension was 2.5-3 cm in two cases and 1-1.5 cm in the other case. In all cases, MRI revealed an acute (isointense signal on T1-weighted and hypointense signal on T2-weighted sequences) or subacute (hyperintense signal on T1 - and T2-weighted sequences) hemorrhage with, adjacent to it, an area with signals of blood of different ages, highly suggestive of CH. CT showed, in chiasmatic CHs, a suprasellar mass spontaneously denser than adjacent brain parenchyma. In two cases, microcalcifications were associated. In two cases, CT and MRI revealed slight heterogeneous enhancement after contrast agent administration. In one case, no enhancement was observed. Two patients underwent surgery by frontopterional craniotomy. The optic chiasms were swollen with an intrinsic bluish mass. The cerebrospinal fluid was not xanthochromic. Microscope examination confirmed the diagnosis of CH. After 12 months, the operated patients had improved visual acuity and visual field but did not completely recover. The nonoperated patient (because of spontaneous rapid recovery of visual acuity) was followed clinically and on MRI over 18 months.

CONCLUSION

CH in the optic chiasm must be suspected in the presence of an acute chiasmatic syndrome. MRI is the best imaging modality, showing either an acute or a subacute chiasmatic hemorrhage or the typical pattern of CH with heterogeneous alternation of foci of blood of different ages, with a central focus of methemoglobin, a peripheral rim of hemosiderin, adjacent foci of acute or subacute hemorrhage, and slight or no enhancement after gadolinium administration.