Atypical lymphoid proliferation of the orbit

Abstract

Objective: Lymphoproliferative disorders are a group of lesions characterized by abnormal proliferation of lymphocytes. In the orbit, they can occur in the ocular adnexae. These neoplasms have defined clinical and pathologic characteristics and account for more than 20% of all orbital tumors. Several types of lymphoproliferative lesions have been described in the orbit. One example is lymphoid hyperplasia, which commonly involves the lacrimal gland. A benign lesion like lymphoid hyperplasia will show a general normal archetype of the tissues-involved lacrimal gland. We expect a polyclonal group of cells with more or less normal architecture of a follicle. On the other hand, lymphoma will show less organized arrangement of cells, and we expect them to be of monoclonal lineage. Methods: This is a case report of a 55-year-old Filipino female who came in for blurring of vision of both eyes. During her assessment, there was an incidental finding of bilateral upper eyelid swelling, and a 30x15 mm palpable firm mass under the right superior orbital rim and a 30x10 mm mass under the left were noted. The right globe was displaced inferiorly, but no proptosis was seen on exophthalmometry. On plain CT scan, we noted a homogenous mass with molding or contouring around the orbital structures. On coronal view, we noted homogenous masses that mold around the globe and recti, and this also confirmed on axial cuts. A section biopsy was done via anterior orbitotomy. Results: Our patient’s histopath had features of both. On scanning magnification, we noted a very cellular round cell tumor. The round cell lesion seemed to be reminiscent of a germinal center of a lymph node. Around it we noticed the glandular structures, which were expected, since this specimen was from the lacrimal gland. A closer view of the lesion on high power showed these lymphocytes within a germinal center. These are large macrophages that actively phagocytose apoptotic lymphoid cells in germinal centers. We expect to see a lot of them in benign hyperplasia, but only a few will be present in malignancies. In summary, our patient had both benign and malignant features, resulting in a histopath result of atypical lymphoid proliferation. Conclusion: Atypical lymphoid proliferation is a rare orbital tumor with benign and malignant features. There is no standard protocol for treatment, and proper multi-specialty coordination is important. External beam radiation therapy with linear accelerator (LINAC) appears to be an effective treatment, with no recurrence in our patient after 5 months.