Extranodal marginal zone lymphoma of the ocular adnexa

Abstract

Lymphomas of the ocular adnexa are a heterogeneous group of malignancies, composing approximately 1% to 2% of non-Hodgkin lymphomas (NHLs) and 8% of extranodal lymphomas. The most common subtype, accounting for up to 80% of cases of primary ocular adnexal lymphoma, is marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type. In the recent past, there have been significant advances in our understanding of the clinical characteristics, morphology and phenotype, etiology, pathogenesis, diagnosis, natural history, treatment approaches, outcome, and prognostic factors of this disease entity. Novel immunologic and molecular techniques have aided in the distinction between MALT lymphoma and other lymphoproliferative disorders and led to the identification of tissue markers of prognostic significance. Modern imaging modalities provide invaluable tools for accurate staging and treatment planning. Besides radiotherapy and chemotherapy, a variety of new treatment options have emerged in the management of patients with ocular adnexal MALT lymphoma, especially monoclonal antibody therapy and antibiotic therapy against Chlamydia psittaci, which has been associated with the pathogenesis of ocular adnexal lymphomas in some parts of the world. In this review, we present a state-of-the-art summary of ocular adnexal MALT lymphomas.

Figure 1

Histologic findings in OAML. (A) Diffuse infiltration of the conjunctiva by a dense small lymphocytic cell population (hematoxylin and eosin, original magnification ×100). (B) Monocytoid cells arranged in sheets in an orbital mass with plasma cell and a Russell body (; hematoxylin and eosin, original magnification ×1000). (C) Lymphoepithelial lesion in lacrimal gland (hematoxylin and eosin, original magnification ×500). (D) Centrocyte-like cells, plasma cells, and Dutcher body () beneath conjunctival epithelium (hematoxylin and eosin, original magnification ×1000). Images of immunohistochemical staining were acquired using a Nikon Eclipse E400 microscope (Nikon) and a Nikon DS-Li digital camera. Digitized images were processed using Adobe Photoshop 7 image processing and manipulation software (Adobe Systems).

Figure 2

Clinical presentations of OAML. Conjunctival MALT lymphoma with involvement of the nasal bulbar conjunctiva (A) and inferior fornix (B).

Figure 3

Radiographic presentations of OAML. (A) CT image of right orbital MALT lymphoma involving the inferior rectus muscle, causing mild proptosis. (B) MRI of left orbital MALT lymphoma involving the lateral and inferior rectus muscles, causing medial deviation of the optic nerve, with involvement of the cavernous sinus (white arrow) and mild dural enhancement in the medial anterior cranial fossa (black arrow). Analysis of the cerebrospinal fluid was positive for lymphoma. This case represents an unusual extension of OAML into the central nervous system leading to lymphomatous meningitis.

Figure 4

Radioimmunotherapy with Y-90 ibritumomab tiuxetan (Zevalin). Pretreatment (A) and posttreatment (B) CT imaging of a patient with OAML involving the right orbit (arrow), demonstrating a complete response 12 weeks after radioimmunotherapy.