Analyses of cell surface markers using FCM were useful in differentiating EMZL from IgG4-ROD/IOI. Sensitivity of Ig light chain restriction was relatively low in diagnosis of EMZL using FCM.

Purpose Relentless placoid chorioretinitis (RPC) is a new disease concept that was proposed by Jones et al. in 2000. Some cases of RPC have been reported; however, a treatment strategy has not yet been established. We report herein four cases of patients diagnosed with RPC. Observations We experienced four cases of RPC in patients aged 24–51 years. All patients exhibited retinal lesions similar to that seen in acute posterior multifocal placoid pigment epitheliopathy or serpiginous choroiditis from the posterior pole to the surrounding region. Although patients underwent systemic prednisolone (PSL) therapy, recurrence was observed and the retinal scar formation was progressive; they were then diagnosed with RPC. In all cases, cyclosporine (CyA) was administered in addition to PSL, no recurrence was observed thereafter. Conclusions and Importance RPC is a rare disease, and a treatment strategy has not yet been established. CyA and PSL combination therapy is considered to be effective in the treatment of RPC.