Clinicopathologic and Magnetic Resonance Imaging Analysis of a Multifocal Orbital Lymphoid Tumor.

Objective: To distinguish between a multifocal orbital lymphoid tumor and a major simulator represented by a diffuse lymphaticovenous malformation.

Methods: We performed a comparison of clinical and radiographic (magnetic resonance imaging [MRI]) findings of these two disparate entities and demonstrated how a misdiagnosis can be prevented.

Results: Orbital lymphoid tumors develop in adults at around 60 years of age, whereas extensive lymphaticovenous malformations are generally detected in the first decade. Despite these differences, this is the first description of clinical confusion between them. MRI with gadolinium injection in the current lymphoid tumor displayed a low signal on T2-weighted images, rapid and uniform enhancement, and reduced diffusion. Lymphaticovenous malformations are heterogeneous, display poor or only focal perfusion, and fail to exhibit diminished diffusion. Newer techniques such as diffusion-weighted imaging and dynamic contrast-enhanced imaging may be able to provide additional differential diagnostic information. The final pathologic diagnosis was an extranodal marginal zone lymphoma.

Conclusions: Despite the obvious distinctions between orbital lymphoid tumors and lymphaticovenous malformations, several clinical radiologic specialists misdiagnosed the present orbital lesion as a vascular lesion. A combined clinicoradiographic analysis should obviate such errors and facilitate the correct diagnosis in the future.