Kurita D, et al. - The clinicopathologic characteristics, outcomes, and prognostic factors for histologic types of methotrexate (MTX)-associated lymphoproliferative disorders (LPDs) were investigated via analyzing paraffin-embedded tissue samples of 219 patients with MTX-LPD. Researchers noted reactive lymphoid hyperplasia (RH), polymorphic-LPD (Poly-LPD), diffuse large B-cell lymphomas (DLBCLs), and classic Hodgkin lymphoma (CHL), in total, 30,33,106, and 26, respectively. RH, Poly-LPD, DLBCLs, and CHL had following clinicopathologic features: extranodal involvement: 13.8% (4/29), 36.4% (12/33), 69.5% (73/105), and 15.4% (4/26); Epstein-Barr virus encoded RNA positivity: 55.2% (16/29), 71.9% (23/32), 45.3% (48/106), and 76.9% (20/26); necrosis: 0% (0/29), 51.5% (17/33), 34.3% (36/105), and 12.0% (3/25); and Hodgkin Reed-Sternberg-like cells: 17.2% (5/29), 50% (14/28), and 19.8% (21/106). RH, Poly-LPD, DLBCLs, and CHL had the median duration from MTX withdrawal to the time of disease regression of 10.4, 3.0, 4.2, and 2.7 months, respectively. Following MTX withdrawal, the greatest progression-free survival was noted for RH, followed by for Poly-LPD, DLBCL, and CHL. The groups did not differ significantly regarding overall survival. The predictive factors for progression-free survival were plasma cell infiltrate for CHL, eosinophil infiltrate, age above 70 years, and extensive necrosis for Poly-LPD on univariate analysis, while on multivariate analysis, these comprised Epstein-Barr virus encoded RNA positivity and International Prognostic Index risk for DLBCL.