Focal Isolated Extraocular Muscle Lymphoma

Abstract

A 61-year-old woman presented with a painless left subconjunctival nodule (Fig A). Magnetic resonance imaging revealed a heterogeneously enhancing mass at the insertion of the left medial rectus muscle on postcontrast T1-weighted images (Fig B). Incisional biopsy was performed. Histopathology demonstrated fibrous tissue with atypical lymphoid infiltrate (Fig C, Hematoxylin and eosin stain) and positive CD20 (Fig D) and BCL-2 staining consistent with extranodal marginal zone lymphoma (EMZL). The patient was treated with external beam radiotherapy with complete remission.