Intraorbital malignant lymphoma presenting with tumor stain on angiography--case report.

A 58-year-old male presented with a 1 month history of left retro-orbital pain and diplopia. Computed tomography demonstrated an isodense intraorbital tumor with slight homogeneous enhancement. Magnetic resonance imaging showed the tumor was isointensity on T1-weighted imaging, slightly high intensity on T2-weighted imaging, and slightly enhanced by gadolinium-diethylenetriaminepenta-acetic acid. Left external carotid angiography showed a tumor stain fed from the branches of the left internal maxillary artery. The tumor was partially removed. The histological diagnosis was malignant lymphoma. Tumor staining is rare in intraorbital malignant lymphoma and is not adequate for differential diagnosis of intraorbital tumors, so biopsy is essential.