Successful Treatment of Methotrexate-associated Lymphoproliferative Disorder with the Pola-R-CHP Regimen.

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) constitutes a subset of lymphoid proliferations and lymphomas that are associated with immune deficiency and dysregulation. The clinical management of MTX-LPDs is contingent on their histopathological subtypes. Polatuzumab vedotin is a novel therapeutic approach that is particularly beneficial for selecting patients with previously untreated diffuse large B-cell lymphoma (DLBCL); however, DLBCL-type MTX-LPD is still treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) because of the exclusion of MTX-LPD from clinical trials. We recently encountered a case of DLBCL-type MTX-LPD with parathyroid hormone-related protein-C (PTHrP)-mediated hypercalcemia that was managed with polatuzumab vedotin, rituximab, cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP). We herein report our experience to encourage hematologists to explore the safe and effective use of Pola-R-CHP under such conditions.