Waldenström macroglobulinemia with secondary pure red cell aplasia in a patient with metastatic castrate resistant prostate cancer receiving an immune checkpoint inhibitor: a case report.

In this case, underlying WM was uncovered through systematic investigation of anemia caused by ICI therapy. This report highlights the possibility of a lymphoproliferative disorder in patients with concerns for PRCA with prior ICI exposure. If identified, treating the underlying lymphoproliferative disorder is highly efficacious in the management of the secondary PRCA.