MYD88^L265P and CXCR4^WHIM mutations are highly prevalent in Waldenström’s macroglobulinemia. MYD88^L265P triggers tumor-cell growth through Bruton’s tyrosine kinase, a target of ibrutinib. CXCR4^WHIM mutations confer in vitro resistance to ibrutinib.

Bruton tyrosine kinase (BTK) inhibition is an effective treatment approach for patients with Waldenström macroglobulinemia (WM). The phase 3 ASPEN study compared the efficacy and safety of ibrutinib, a first-generation BTK inhibitor, with zanubrutinib, a novel highly selective BTK inhibitor, in patients with WM. Patients with MYD88L265P disease were randomly assigned 1:1 to treatment with ibrutinib or zanubrutinib. The primary end point was the proportion of patients achieving a complete response (CR) or a very good partial response (VGPR) by independent review. Key secondary end points included major response rate (MRR), progression-free survival (PFS), duration of response (DOR), disease burden, and safety. A total of 201 patients were randomized, and 199 received ≥1 dose of study treatment. No patient achieved a CR. Twenty-nine (28%) zanubrutinib patients and 19 (19%) ibrutinib patients achieved a VGPR, a nonstatistically significant difference (P = .09). MRRs were 77% and 78%, respectively. Median DOR and PFS were not reached; 84% and 85% of ibrutinib and zanubrutinib patients were progression free at 18 months. Atrial fibrillation, contusion, diarrhea, peripheral edema, hemorrhage, muscle spasms, and pneumonia, as well as adverse events leading to treatment discontinuation, were less common among zanubrutinib recipients. Incidence of neutropenia was higher with zanubrutinib, although grade ≥3 infection rates were similar in both arms (1.2 and 1.1 events per 100 person-months). These results demonstrate that zanubrutinib and ibrutinib are highly effective in the treatment of WM, but zanubrutinib treatment was associated with a trend toward better response quality and less toxicity, particularly cardiovascular toxicity.

Patients with double-hit lymphoma (DHL), which is characterized by rearrangements of MYC and either BCL2 or BCL6, face poor prognoses. We conducted a retrospective multicenter study of the impact of baseline clinical factors, induction therapy, and stem cell transplant (SCT) on the outcomes of 311 patients with previously untreated DHL. At median follow-up of 23 months, the median progression-free survival (PFS) and overall survival (OS) rates among all patients were 10.9 and 21.9 months, respectively. Forty percent of patients remain disease-free and 49% remain alive at 2 years. Intensive induction was associated with improved PFS, but not OS, and SCT was not associated with improved OS among patients achieving first complete remission (P = .14). By multivariate analysis, advanced stage, central nervous system involvement, leukocytosis, and LDH >3 times the upper limit of normal were associated with higher risk of death. Correcting for these, intensive induction was associated with improved OS. We developed a novel risk score for DHL, which divides patients into high-, intermediate-, and low-risk groups. In conclusion, a subset of DHL patients may be cured, and some patients may benefit from intensive induction. Further investigations into the roles of SCT and novel agents are needed. Key Points A subset of DHL patients may be cured, and some patients may benefit from intensive induction. Further investigations into the roles of SCT and novel agents are needed.

Plasmablastic lymphoma (PBL) is an aggressive lymphoma commonly associated with HIV infection. However, PBL can also be seen in patients with other immunodeficiencies as well as in immunocompetent individuals. Because of its distinct clinical and pathological features, such as lack of expression of CD20, plasmablastic morphology, and clinical course characterized by early relapses and subsequent chemotherapy resistance, PBL can represent a diagnostic and therapeutic challenge for pathologists and clinicians alike. Despite the recent advances in the therapy of HIV-associated and aggressive lymphomas, patients with PBL for the most part have poor outcomes. The objectives of this review are to summarize the current knowledge on the epidemiology, biology, clinical and pathological characteristics, differential diagnosis, therapy, prognostic factors, outcomes, and potential novel therapeutic approaches in patients with PBL and also to increase the awareness toward PBL in the medical community.

Purpose: Breast implant–associated anaplastic large-cell lymphoma (ALCL) is a recently described clinicopathologic entity that usually presents as an effusion-associated fibrous capsule surrounding an implant. Less frequently, it presents as a mass. The natural history of this disease and long-term outcomes are unknown. Patients and Methods: We reviewed the literature for all published cases of breast implant–associated ALCL from 1997 to December 2012 and contacted corresponding authors to update clinical follow-up. Results: The median overall survival (OS) for 60 patients was 12 years (median follow-up, 2 years; range, 0-14 years). Capsulectomy and implant removal was performed on 56 of 60 patients (93%). Therapeutic data were available for 55 patients: 39 patients (78%) received systemic chemotherapy, and of the 16 patients (28%) who did not receive chemotherapy, 12 patients opted for watchful waiting and four patients received radiation therapy alone. Thirty-nine (93%) of 42 patients with disease confined by the fibrous capsule achieved complete remission, compared with complete remission in 13 (72%) of 18 patients with a tumor mass. Patients with a breast mass had worse OS and progression-free survival (PFS; P = .052 and P = .03, respectively). The OS or PFS were similar between patients who received and did not receive chemotherapy (P = .44 and P = .28, respectively). Conclusion: Most patients with breast implant–associated ALCL who had disease confined within the fibrous capsule achieved complete remission. Proper management for these patients may be limited to capsulectomy and implant removal. Patients who present with a mass have a more aggressive clinical course that may be fatal, justifying cytotoxic chemotherapy in addition to removal of implants.