Immunophenotypic profiles for distinguishing orbital mucosa-associated lymphoid tissue lymphoma from benign lymphoproliferative tumors.

ABSTRACT

PURPOSE: To evaluate novel immunophenotypic profiles of patients with orbital lymphoproliferative tumors. METHODS: From 2006 to 2014, surgical biopsies from consecutive patients with newly diagnosed orbital mucosa-associated lymphoid tissue (MALT) lymphoma and IgG4-related ophthalmic disease (IgG4-ROD) were collected from Tokyo Medical University Hospital. A total of 44 tumors from 44 patients were analyzed, including 21 with orbital MALT lymphoma (11 men and 10 women, mean age 67.8 ± 13.4 years) and 23 with definitive IgG4-ROD (9 men and 14 women, mean age 60.5 ± 15.1 years). Patients with secondary orbital MALT lymphoma and MALT lymphoma with IgG4-ROD were excluded. All patients were immunocompetent Asian adults. Samples were analyzed by immunohistochemistry and flow cytometric analysis. Flow cytometry was performed with the following antibodies CD3, CD4, CD5, CD8, CD10, CD19, CD20, CD23, CD25, CD30, CD34, and CD56 lambda and kappa chains. RESULTS: Expression of CD25 and CD19 was higher in patients with orbital MALT lymphoma compared to patients with IgG4-ROD (p < 0.001). In contrast, expression of CD3, CD4, and CD23 was higher in patients with orbital IgG4-ROD compared to those with MALT lymphoma (all p < 0.01). The presence of CD23 and CD25 in the specimens was confirmed by immunohistochemistry. CONCLUSION: The present study elucidated the novel immunophenotypic features of orbital MALT and benign lymphoproliferative disorders such as IgG4-ROD. Among them, CD23 and CD25 have shown a disease-specific expression pattern.