Majority of orbital lymphomas are of B-cell origin

This retrospective interventional case series characterized the clinical features of subtype-specific orbital lymphoma.

Study design

This study spanned 7 international eye cancer centers and included 797 patients with histologically verified orbital lymphoma. Primary endpoints were overall survival, disease-specific survival and progression-free survival.

Outcomes

The median age of patients in the study was 64 years and approximately half of the cohort was male (51%). The most frequent subtype was extranodal marginal zone B-cell lymphoma (EMZL; 57%) followed by diffuse large B-cell lymphoma (DLBCL; 15%), follicular lymphoma (FL; 11%) and mantle cell lymphoma (MCL; 8%).

Focal EMZL and FL were often treated with radiation therapy whereas DLBCL, MCL and disseminated EMZL and FL were managed using chemotherapy. Patients diagnosed with EMZL and FL had a better prognosis than patients with DLBCL and MCL (92% and 71% vs 41% and 32%). The main predictor for disease outcome was histological subtype.

Limitations

Although this is a large study, the data was collected between January 1980 and December 2017. Methods of detection and treatment have changed during the last decade when compared with the 1980s and 1990s. The reports of the stages and treatments of earlier patients may therefore not be valid and may have affected the final results.

Clinical significance

This series agrees with earlier studies suggesting that EMZL is the most common subtype of orbital lymphoma, followed by DLBCL, FL and MCL. It also highlights that DLBCL and MCL patients tend to have a worse prognosis compared with EMZL and FL.