Orbital fibrous histiocytoma mimicking cavernous hemangioma on dynamic contrast-enhanced MRA imaging.

Orbital lesions include a broad spectrum of tumors, vascular abnormalities, and inflammatory conditions. High-resolution imaging has become an invaluable tool toward formulating an accurate diagnosis, and facilitates proper counseling regarding appropriate interventions. Imaging may guide whether partial excision to minimize damage to orbital structures, or en bloc removal to prevent potential recurrence, as seen in mesenchymal tumors, is indicated., Recently, dynamic contrast-enhanced magnetic resonance angiography (MRA) has demonstrated use in helping differentiate orbital vascular lesions. This imaging modality uses rapid MRI acquisition to provide noninvasive, dynamic flow information with high spatial resolution. However, even with modern imaging, reaching a diagnosis prior to histopathological analysis can be challenging. We present a case of orbital fibrous histiocytoma that appeared nearly identical to cavernous hemangioma on dynamic contrast-enhanced MRA.