Primary treatment of patients with HCL in the Netherlands according age at diagnosis and calendar period of diagnosis, 1989 to 2015. The table presents the proportion of patients receiving a particular treatment within a specific calendar period and age group. The absolute number of patients within a specific calendar period and age group is shown in supplemental Table 1. Sixteen (3.7%) of the 430 patients with HCL who did not receive antineoplastic therapy underwent splenectomy. Of note, detailed data from patients diagnosed during 2014 to 2015 revealed that all PNA recipients were treated with cladribine, of whom 1 received cladribine in combination with rituximab. Further, 3 patients received rituximab monotherapy, and 1 patient received IFN-α.