Ocular Adnexal MALT Lymphomas : Morphology
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Ocular Adnexal Lymphomas - Morphology: Vast majority of primary ocular adnexal lymphomas are B-cell non-Hodgkin lymphomas (98%). About 60-75% are extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (or MALT lymphomas), followed by follicular lymphomas (10%) and diffuse large B-cell lymphoma (9%). Rare examples of mantle cell lymphoma, Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, B-lymphoblastic lymphoma, and NK/T-cell lymphoma have been documented.
The morphologic and immunophenotypic features of ocular adnexal MALT lymphomas are similar to other MALT lymphomas. MALT lymphomas of orbital soft tissue often infiltrate orbital fat, blood vessels, and nerves. The conjunctival MALT lymphomas show lymphoepithelial lesions which consist of neoplastic lymphocytes infiltrating conjunctival epithelium overlying the tumor. The differential diagnosis includes: reactive lymphoid hyperplasia, inflammatory pseudotumor, chronic (allergic) conjunctivitis, and granulomatous conjunctivitis.
This conjunctival biopsy with MALT lymphoma shows sheets of uniform neoplastic marginal zone cells.
The morphologic and immunophenotypic features of ocular adnexal MALT lymphomas are similar to other MALT lymphomas. MALT lymphomas of orbital soft tissue often infiltrate orbital fat, blood vessels, and nerves. The conjunctival MALT lymphomas show lymphoepithelial lesions which consist of neoplastic lymphocytes infiltrating conjunctival epithelium overlying the tumor. The differential diagnosis includes: reactive lymphoid hyperplasia, inflammatory pseudotumor, chronic (allergic) conjunctivitis, and granulomatous conjunctivitis.
This conjunctival biopsy with MALT lymphoma shows sheets of uniform neoplastic marginal zone cells.