Bilateral Extraocular Muscle B-Cell Lymphoma in an Elderly Male.

Abstract

e106 Ophthalmic Plast Reconstr Surg, Vol. 36, No. 4, 2020 An otherwise healthy 82-year-old male presented with painless binocular diplopia for 6 weeks and worsening vision in the left eye for 3 days. Visual acuity was 20/20 OD and count fingers at 3 feet OS with a left relative afferent pupillary defect. He had a left hypertropia (Fig. A) and significant limitation in supraduction OD, and supraduction, adduction and abduction OS. Orbital CT demonstrated nonuniform enlargement of the right superior rectus muscle anteriorly (Fig. B1) and the left lateral rectus muscle posteriorly (Fig. B2) with tendon sparing and significant mass effect on the left optic nerve at the apex. Biopsy of the left lateral rectus muscle was consistent with marginal zone B-cell lymphoma (Fig. C). The optic neuropathy resolved completely following intravenous steroids and R-mini CHOP chemotherapy (Rituxamab and reduced dose cyclophosphamide, doxorubicin, vincristine, and prednisone). His motility defects resolved other than a persistent −2 deficit in abduction OS. Workup for metastasis was negative. Orbital lymphoma is the most common primary orbital malignancy, with marginal zone B-cell lymphoma being the most common histologic subtype. Extraocular muscle is the least common site of involvement and bilateral involvement is extremely rare.