Abstract
PURPOSE: To report a case of marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in the bilateral orbit with chronic hepatitis B virus (HBV) infection. OBSERVATIONS: A 72-year-old man with chronic HBV infection presented with a bilateral proptosis with slight restriction of ocular motility for 9 months. Computed tomographic images showed well-defined, isodense masses in the bilateral superolateral orbit. Magnetic resonance images showed isointense on T1-and hyperintense on T2-weighted images, with bilateral involvements of the lateral rectus muscles reaching the superior orbital fissures. These masses molded along the globe contour. Incisional biopsies via upper eyelid crease were performed on both lesions. The immunohistopathological diagnosis was MALT lymphoma. CONCLUSIONS AND IMPORTANCE: This case showed a possible association between orbital MALT lymphoma and HBV.