The coexistence of neuropsychiatric systemic lupus erythematosus (NPSLE) and primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) (PCNS DLBCL) is extremely rare in clinical practice. This article retrospectively analyzes the clinical manifestations, imaging examinations, pathological diagnosis, and treatment process of a patient with NPSLE, from the appearance of intracranial abnormal signal shadows to the final diagnosis of PCNS DLBCL. A 32-year-old Chinese female patient had previously visited our hospital due to vomiting and delirium and was diagnosed with NPSLE. In February 2021, she returned to our hospital with vomiting again. Laboratory tests revealed elevated infection markers and Epstein-Barr virus infection. Brain CT and MRI showed an abnormal intracranial lesion on the left side, which was initially considered to be a brain abscess. After one week of ineffective anti-infection treatment, the patient underwent surgery, during which the lesion was identified as a brain tumor and successfully resected. The final diagnosis was PCNS DLBCL. The patient improved after treatment and was discharged from the hospital. There has been no recurrence of NPSLE or lymphoma within three years. When patients with NPSLE develop new intracranial lesions, misdiagnosis is likely to occur. Imaging and pathology are crucial, and clarifying the nature of the lesion is conducive to a good long-term prognosis.

In this study, we compare outcomes of older patients with primary diffuse large B-cell lymphoma of the central nervous system (PCNSL) undergoing autologous hematopoietic cell transplantation (autoHCT) with either thiotepa/carmustine (BCNU/Thio) or thiotepa/busulfan/cyclophosphamide (TBC) conditioning. We used a postpublication dataset made available by the Center for International Blood and Marrow Transplantation Research including patients who were ≥65 years in age with PCNSL and underwent autoHCT as consolidation with TBC or BCNU/Thio conditioning. Out of 147 patients; n = 84 received BCNU/Thio and n = 63 received TBC. The 1-year NRM in the BCNU/Thio group was 10% versus 22% in the TBC group (P = .05) and the 2-year relapse rate was 5% versus 5%, respectively (P = 1.00). The 2-year progression-free survival (PFS) in the BCNU/Thio group was 85% versus 71% in the TBC group (P = .05) and 2-year overall survival (OS) was 86% versus 74% (P = .08). In a multivariable regression model, BCNU/Thio was associated with a lower risk for NRM (hazard ratio [HR], 0.33, P = .009), improved PFS (HR, 0.41, P = .008) and OS (HR, 0.37, P = .007), but there was no association with relapse risk. We found that in older adults with PCNSL undergoing consolidation with autoHCT, BCNU/Thio conditioning is associated with lower NRM and improved OS compared to TBC.

Primary diffuse large B-cell lymphoma of the central nervous system (CNS-DLBCL) can be difficult to diagnose because of the limited amount of biopsy tissue. Here, we analyzed the utility of insulin-like growth factor II mRNA binding protein 3 (IMP3) immunohistochemistry (IHC) as an adjunctive diagnostic tool for CNS-DLBCL. IHC was performed on 57 biopsy samples (55 brain biopsy samples and two vitreous cell blocks) from 54 patients with CNS-DLBCL, including three biopsy samples initially diagnosed as negative or indeterminate for CNS-DLBCL. Additionally, IMP3 IHC was performed on 68 DLBCLs other than CNS-DLBCL and 12 inflammatory brain diseases. Cytoplasmic IMP3 expression was noted in ≥50% of tumor cells in 100% (57/57) of CNS-DLBCLs and 88.2% (60/68) of non-CNS-DLBCLs. In contrast, no IMP3-positive CD20-positive B cells were observed in the inflammatory brain disease (P < 0.0001). In conclusion, IMP3 is highly expressed in CNS-DLBCL. However, it is also expressed in other types of DLBCLs, making it less specific. Most CNS-DLBCL cases can be diagnosed without performing IHC for IMP3 expression, but it may be a useful adjunctive tool to differentiate from reactive lesions when tumor cells are few or deformed.

The MATRix chemoimmunotherapy regimen is highly effective in patients with newly diagnosed primary diffuse large B-cell lymphoma of the central nervous system (PCNSL). However, nothing is known about its feasibility and efficacy in everyday practice, where patients are more often older/frailer than those enrolled in clinical trials. We conducted a retrospective study addressing tolerability/efficacy of MATRix in 156 consecutive patients with newly diagnosed PCNSL treated outside a clinical trial. Median age and ECOG Performance Status of considered patients were 62 years (range 28-78) and 2 (range 0-4). The overall response rate after MATRix was 79%. Nine (6%) treatment-related deaths were recorded. After a median follow-up of 27.4 months (95% confidence interval [CI] 24.4-31.9%), the two-year progression-free and overall survival were 56% (95% CI 48.4-64.9%) and 64.1% (95% CI 56.7-72.5%) respectively. Patients not eligible for the IELSG32 trial were treated with lower dose intensity and had substantially worse outcomes than those fulfilling inclusion criteria. This is the largest series of PCNSL patients treated with MATRix outside a trial and recapitulates the IELSG32 trial outcomes in the non-trial setting for patients who fit the trial criteria. These data underscore the feasibility and efficacy of MATRix as induction treatment for fit patients in routine practice.

Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a rare entity which is difficult to diagnose and treat. The histone methyltransferase EZH2 was reported to be involved in the tumorigenesis of systemic DLBCL but has not been implicated in primary CNS DLBCL. The clinicopathological features of 33 cases of primary CNS DLBCL and expression of EZH2 and Y641 mutation were assessed. The tumor cells of the majority cases resembled centroblasts, and intriguingly, three cases of rare anaplastic variant were observed. Immunophenotypically, 25/33 (75.8%) cases were non-germinal center B-cell-like type. Several cases (10/33; 30.3%) co-expressed BCL2 and MYC, 6/33 (18.2%) expressed both BCL6 and MYC, and 5/33 (15.2%) expressed BCL2, BCL6, and MYC. MYC expression alone and BCL2/MYC co-expression were associated with poor prognosis. EZH2 was strongly expressed in all 33 cases independent of Y641 mutation and was significantly associated with the tumor proliferative index Ki67. However, no association was found between the level of EZH2 expression and outcomes of patients. In summary, the clinicopathological features including three rare anaplastic variant of primary CNS DLBCL are described. Strong expression of EZH2 in all the primary CNS DLBCL and association with high proliferative index provides further information for treatment and diagnosis of this distinctive entity.