Bilateral development of biclonal ocular adnexal marginal zone lymphoma at a 2-year interval

Ocular adnexal marginal zone B-cell lymphoma (OAMZL) of the mucosa-associated lymphoid tissue is a distinct subtype of B-cell lymphoma. OAMZL occasionally occurs on both sides with a varied sequence in the time course. However, few case reports have described clonal analysis of bilateral OAMZ. Here we present a case of biclonal OAMZL, that developed bilaterally at a 2-year interval. A 38-year-old woman was diagnosed with OAMZL in the right lower eyelid conjunctiva and received local radiation therapy, resulting in the disappearance of the tumor. Two years later, she developed another tumor in the left lower eyelid and was diagnosed with relapse of OAMZL. She was re-treated successfully with radiation therapy. Analysis of immunoglobulin (Ig) gene rearrangement in the bilateral tumor samples showed different clonotypic VDJ recombination within the Ig heavy chain gene and different patterns of rearrangement of the Ig light chain genes. The results indicated that independent B-cell clones causing the specific subtype of lymphoma had generated in both eyes. The biclonal nature of the lymphoma that developed sequentially in the same anatomic site in this case suggests that underlying inherent or environmental factors may lead to ongoing emergence of new tumor clones.