In this study the authors compare primary ocular adnexal (OA) mantle cell lymphoma (MCL) with initially systemic MCL occurring over a 30-year period. MCL is a rare form of lymphoma accounting for 5-11% of OA lymphomas and therefore knowledge of disease outcomes is limited. Patients were more typically male (5:1) and in their mid-60s. Patients presented with a mass, periorbital oedema or proptosis most commonly in both groups with the most common tumour location being the lacrimal gland (OA 57%, systemic 48%). Conjunctival involvement occurred more frequently in the primary OA MCL group (52% versus 19%). Survival rates were similar in the two groups and higher than previously reported (five-year DSS 87%). The authors also found that patients without disease recurrence most often received initial rituximab-based chemotherapy with autologous stem cell transplant than those with disease recurrence.