Lymphoma represents only 6-8% of all orbital masses. Its incidence is estimated to have been rising over the last two decades. We describe the imaging feature of small and large diffuse B-cell primary lymphoma, which was found in the extra-conal orbital space. Imaging findings of lesion, depicted on Computed Tomography and Magnetic Resonance were suggestive of the presence of a soft-tissue neoplasm: the isolated appearance of our single orbital lesion made this a challenging diagnosis for radiologists and clinicians.

A brief review – emphasizing imaging features – is reported in this manuscript, in order to increase diagnostic confidence of clinicians, radiologists and surgeons.