Ocular/adnexal lymphoma: dissimilar to systemic lymphoma

Ocular adnexal lymphoma and intraocular lymphoma, whether occurring simultaneously or sequentially, are often similar to associated systemic lymphoma. We describe 4 cases of ocular adnexal lymphoma or intraocular lymphoma with a dissimilar systemic lymphoma. Two of the cases represent Richter transformation of chronic lymphocytic leukemia/small-cell lymphoma into diffuse large B-cell lymphoma. In the third patient, conjunctival extranodal marginal zone lymphoma developed following treatment for Hodgkin lymphoma. The fourth patient had a remote history of systemic diffuse large B-cell lymphoma with a subsequent diagnosis of orbital extranodal marginal zone lymphoma. Clinical-pathological correlation is reported for all cases in addition to pertinent review of the literature.