Ocular adnexal lymphoma - a retrospective study and review of the literature.

Background: To review the characteristics of all Slovenian patients with ocular adnexal lymphoma (OAL) in the period of 24 years with the aim of evaluating demographic data, lymphoma location and type, disease stage, treatment modality, local control rate and survival rate.

Patients And Methods: All patients with histologically diagnosed OAL in the main tertiary centre of Slovenia, Eye Hospital, University Medical Centre Ljubljana, who were treated at Institute of Oncology Ljubljana were included in the study. Patients' data were collected from October 1995 through April 2019.

Results: Seventy-four patients were included in the study having a median age of 68 years at diagnosis. The majority of lymphomas were of B-cell origin (98.6%). The most frequent type was the extranodal marginal zone B-cell lymphoma (MALT) (71.6%). Orbital lymphomas were diagnosed in 56 cases (75.7%) and conjunctival in 18 cases (24.3%). Ocular manifestation was the first sign of the disease in 78.4% of patients and in 67.6% of patients ocular adnexa were the only disease location. Fifty-one patients (68.9%) were treated with radiotherapy, 7 patients (9.4%) with systemic treatment, 5 patients (6.8%) with combined radiotherapy and systemic treatment and in 11 patients, biopsy and active surveillance strategy was applied (14.9%). Local control of the disease was achieved in 96.6% of treated patients. Median overall survival of the whole study group has not been reached yet. Five-year overall survival rate was 80.1% (95% CI 68.1% - 88.5%) and 5-year lymphoma specific survival rate was 87.2% (95% CI 83.2%-91.2%).

Conclusions: OALs comprise a group of heterogeneous diseases with variable outcomes depending predominately on the patient's age and lymphoma type, with low grade lymphomas carrying good prognosis even in elderly patients.