Ocular adnexal lymphoma-comparison of MALT lymphoma with other histological types

Abstract

Aims: To correlate histological features of ocular adnexal lymphoma using the revised European American lymphoma classification (REAL), with stage of disease at presentation, treatment modalities, and patient outcome. MALT lymphoma defines an extranodal marginal zone B cell lymphoma as outlined in the REAL classification. Comparison groups of patients included those with primary ocular adnexal MALT lymphoma versus primary ocular adnexal lymphomas of other types, MALT lymphoma versus non-MALT lymphomas (primary and secondary), and primary ocular adnexal lymphoma (MALT lymphomas and other types) versus secondary ocular adnexal lymphomas.

Methods: A retrospective review of the National Ophthalmic Pathology Laboratory records identified 20 cases of ocular adnexal lymphoma over a 10 year period which were reclassified using appropriate immunohistochemical stains. Patients' medical records were examined for data including stage of the disease at presentation, mode of treatment, and patient outcome.

Results: Among the 20 cases identified 14 had primary ocular adnexal lymphomas. 10 of the primary lymphomas had histological features of MALT lymphoma. One case was a primary ocular adnexal T cell lymphoma, one a follicular centre, follicular B cell lymphoma, and two were large cell B cell lymphomas. Six cases had systemic disease, four large B cell, one follicular centre, follicular B cell, and one mantle cell. A significantly higher proportion of patients with MALT lymphomas had early disease (p = 0.005), initially required local treatment (p = 0.005) and were alive at last follow up (p = 0.001) than those without. Two patients with MALT lymphoma had recurrence of lymphoma which responded to further treatment.

Conclusions: Patients with primary ocular adnexal MALT lymphomas present with localised disease requiring local treatment and have a better outcome compared with patients with other types. As a small percentage of these tumours recur, patients should be followed up indefinitely.

Figure 1

(A) Photomicrograph of conjunctival MALT lymphoma, demonstrating a monotonous infiltrate of small round and small cleaved lymphocytes. The remnant of a pre-existing germinal centre has been colonised by tumour cells (large arrow) (haematoxylin and eosin ×40). (B) Photomicrograph of conjunctival MALT lymphoma, stained with the immunohistochemical stain for follicular dendritic cell delineates the skeleton of a pre-existing germinal centre (large arrow) (CD21 ×40). (C) Photomicrograph of conjunctival MALT lymphoma, stained with immunohistochemical stain outlining a lymphoepithelial lesions (a) and highlighting lymphocytic invasion of the mucosal surface (large arrow) (cytokeratin ×400). (D) Photomicrograph of conjunctival MALT lymphoma, stained with an immunohistochemical T cell marker, demonstrating the typically high percentage of T cells in these tumours. Many of the epithelial infiltrating lymphocytes are of T cell phenotype (small arrows) (CD3 ×40).