Orbital Extranodal Marginal Zone Lymphoma Following Radiotherapy: A Report of 2 Cases

Purpose: To present 2 patients in whom orbital radiation preceded the development of periorbital extranodal marginal zone lymphoma by more than a decade and to investigate the likelihood of this representing irradiation-induced malignancy. Methods: Retrospective chart review and histopathologic study with immunohistochemistry of 2 cases. Results: The first patient was a 58-year-old woman who developed an orbital mass within the vicinity of the lateral rectus muscle 17 years after external beam proton radiation therapy for an inferotemporal choroidal melanoma. The second patient was a 32-year-old woman who developed a mass in the right lacrimal gland 12 years after external beam photon radiation therapy for chronic inflammatory dacryoadenitis. Histopathologic and immunohistochemical studies confirmed orbital extranodal marginal zone lymphoma in both cases. Retrospective review of older histopathologic slides from the second patient revealed underlying immunoglobulin G4–related disease. Discussion: The unusual sequence of events in these 2 cases raises the question of whether orbital radiation may in rare instances promote the development of orbital extranodal marginal zone lymphoma. The literature pertaining to irradiation-induced secondary malignancy in the orbit is reviewed. Conclusions: Clinicians should consider the possibility of a secondary malignancy when evaluating a patient with an orbital mass and a history of prior local radiation exposure. Accepted for publication November 5, 2017. Natalie Wolkow is supported by a Heed Ophthalmic Fellowship. The remaining authors have no conflicts of interest to disclose. Address correspondence and reprint requests to Frederick A. Jakobiec, M.D., D.Sc., Department of Ophthalmology, David G. Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Suite 328, Boston, Massachusetts 02114. E-mail: Fred_Jakobiec@meei.harvard.edu © 2018 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.