Bilateral Ocular Adnexal Extranodal Marginal Zone Lymphoma Presenting as Recurrent Conjunctival Inflammation

Abstract

Ocular adnexal lymphomas are uncommon lymphoproliferative disorders, with extranodal marginal zone lymphoma (EMZL) being the predominant subtype. They may mimic chronic conjunctival inflammation, resulting in delayed diagnosis. We report a 49-year-old woman with recurrent bilateral redness and swelling for two years, initially responsive to topical and systemic corticosteroids but subsequently becoming refractory. Spectacle-corrected visual acuity was 20/60 in the right eye and 20/30 in the left eye, with further improvement to 20/30 in the right eye using a scleral contact lens. Mild right axial proptosis was present. Slit-lamp examination showed a diffuse, elevated, smooth, salmon-pink subconjunctival lesion involving the superior bulbar conjunctiva of the left eye. Corneal tomography demonstrated bilateral keratoconus with inferior steepening. Contrast-enhanced orbital MRI revealed bilateral orbital soft-tissue lesions, more prominent on the right. Incisional biopsy of the left conjunctival lesion showed dense lymphoid infiltration with diffuse CD20 and BCL-2 positivity and a Ki-67 proliferation index of approximately 15%, consistent with EMZL. Systemic evaluation, including bone marrow biopsy and immunophenotyping, showed no systemic involvement. A diagnosis of primary bilateral ocular adnexal EMZL with conjunctival and orbital involvement, coexisting with keratoconus was established. The patient received involved-site radiotherapy to both orbits (4 Gy in 2 fractions per orbit), sequentially one week apart. Treatment was well tolerated. At three months after radiotherapy, 18F-FDG PET-CT demonstrated complete metabolic response (Deauville score 1), with resolution of orbital lesions and no disease elsewhere. This case emphasises considering lymphoma in chronic recurrent conjunctival inflammation with transient or diminishing corticosteroid response and documents its uncommon coexistence with keratoconus without implying causality.