Primary central nervous system lymphoma (PCNSL) is a rare brain tumor that most commonly arises in the cerebral white matter, basal ganglia, peri-ventricle or corpus callosum. Confinement of PCNSL to the third ventricle is extremely rare, and seldom presents with intratumoral hemorrhage (ITH). The present study described the case of a 75-year-old woman who presented with obstructive hydrocephalus due to third-ventricle PCNSL. On magnetic resonance imaging (MRI), the tumor presented ITH on T2*-weighted images and a highly elevated regional cerebral blood volume on dynamic susceptibility contrast-enhanced MRI (DSC-MRI). Due to the high elevation of the regional cerebral blood volume, high-grade glioma was suspected as a preoperative diagnosis. The patient underwent endoscopic tumor biopsy and third ventricle PCNSL was successfully diagnosed. The patient achieved good prognosis at an early stage after the start of treatment initiation. There are many differential considerations for a third-ventricle tumor, and DSC-MRI can help the differential diagnosis of these tumors. Furthermore, the presence of ITH can lead to the inaccurate estimation of regional cerebral blood volume values. Overall, silent or microhemorrhage in PCNSL may be underestimated, and clinicians should therefore carefully evaluate tumor vascularity by MRI.

Earlier, prior to the development of effective systemic therapy, monotherapy with whole-brain radiotherapy (WBRT) was widely used to treat primary central nervous system lymphoma (PCNSL). Recently, chemotherapy, especially with high dose methotrexate (HDMTX), has largely replaced WBRT as upfront treatment, and the most accepted standard of care is induction with a combination drug therapy followed by consolidation therapy with either autologous stem-cell transplantation (ASCT) or radiation. Whilst WBRT is an effective component of treatment, it is occasionally associated with risk of permanent, irreversible neurotoxicity when doses of more than 30 Gy are used. Hence, there has been a strong focus on the optimization of radiotherapy (RT) which includes dose reduction in the consolidation phase. In this comprehensive review, we have summarized the progress on clinical results and evidence considering the role and use of radiation including combined treatment modalities, low-dose radiotherapy, and neurotoxicity. Finally, we present a practical approach to low-dose WBRT and boosting higher doses to the gross tumor that can be integrated into clinical practice.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive brain tumor with poor prognosis if no treatment. The activation of the NF-κB (nuclear factor kappa-B) is the oncogenic hallmark of PCNSL, and it was driven by B cell receptor (BCR) and Toll-like receptor (TLR) signaling pathways. The emergence of Bruton\'s tyrosine kinase inhibitors (BTKis) has brought the dawn of life to patients with PCNSL. This review summarizes the management of PCNSL with BTKis and potential molecular mechanisms of BTKi in the treatment of PCNSL. And the review will focus on the clinical applications of BTKi in the treatment of PCNSL including the efficacy and adverse events, the clinical trials currently being carried out, the underlying mechanisms of resistance to BTKi and possible solutions to drug resistance.

OBJECTIVE: Despite the improvement in treatment and prognosis of primary central nervous system lymphoma (PCNSL) over the last decades, the 5-year survival rate is approximately 30%; thus, new therapeutic approaches are needed to improve patient survival. The study\'s aim was to evaluate the role of surgical resection of PCNSL.
METHODS: Primary outcomes were the overall survival (OS) and progression-free survival (PFS) of patients with PCNSL who underwent surgical resection versus biopsy alone. The meta-analysis was conducted to calculate pooled hazard ratios (HRs) under a random-effects model for the time-to-event variables. The odds ratios (ORs) were calculated for binary, secondary outcome parameters.
RESULTS: Seven studies (n = 1046) were included. We found that surgical resection was associated with significantly better OS (HR 0.63 [95% CI 0.51-0.77]) when compared with biopsy. PFS was also significantly improved (HR 0.64 [95% CI 0.49-0.85]) in patients who underwent resection compared with those who underwent biopsy. The heterogeneity for OS and PFS was low (I2 = 7% and 24%, respectively). We also found that patients who underwent biopsy more often had multiple (OR 0.38 [95% CI 0.19-0.79]) or deep-seated (OR 0.20 [95% CI 0.12-0.34]) lesions compared with those who underwent surgical resection. There were no significant differences in chemotherapy or radiotherapy use or the occurrence of postoperative complications between the two groups.
CONCLUSIONS: In selected patients, surgical resection of PCNSL is associated with significantly better overall survival and progression-free survival compared with biopsy alone.

PET imaging is being increasingly used to supplement MRI in the clinical management of brain tumors. The main radiotracers implemented in clinical practice include [18F]FDG, radiolabeled amino acids ([11C]MET, [18F]FDOPA, [18F]FET) and [68Ga]Ga-DOTA-SSTR, targeting glucose metabolism, L-amino-acid transport and somatostatin receptors expression, respectively. This review aims at addressing the current place and perspectives of brain PET imaging for patients who suffer from primary or secondary brain tumors, at diagnosis and during follow-up. A special focus is given to the following: radiolabeled amino acids PET imaging for tumor characterization and follow-up in gliomas; the role of amino acid PET and [18F]FDG PET for detecting brain metastases recurrence; [68Ga]Ga-DOTA-SSTR PET for guiding treatment in meningioma and particularly before targeted radiotherapy.

Primary Central Nervous System Lymphoma (PCNSL) is a rare variant of Non-Hodgkin Lymphoma (NHL) representing 1-2% of all NHL cases. PCNSL is defined as a lymphoma that occurs in the brain, spinal cord, leptomeninges, or eyes. Efforts to treat PCNSL by traditional chemotherapy and radiotherapy have generally been unsuccessful as a significant proportion of patients have frequent relapses or are refractory to treatment. The prognosis of patients with Refractory or Relapsed (R/R) PCNSL is abysmal. The optimal treatment for R/R PCNSL is poorly defined as there are only a limited number of studies in this setting. Several studies have recently shown that ibrutinib, a Bruton tyrosine kinase (BTK) inhibitor, has promising results in the treatment of R/R PCNSL. However, these are preliminary studies with a limited sample size. In this systematic review, we explored and critically appraised the evidence about the efficacy of the novel agent ibrutinib in treating R/R PCNSL.

Primary central nervous system lymphoma (PCNSL) is a rare intracranial neoplasm in older adults. Tumor-associated parkinsonism (TAP) in PCNSL is extremely rare, and its clinical features are unclear. The present report describes the case of a 75-year-old man who presented with parkinsonism due to multiple hyperintense lesions in the thalamus and periventricular white matter as visualized by magnetic resonance imaging (MRI). Due to the rapid progression of parkinsonism and lesion enlargement, the patient underwent stereotaxic biopsy. Subsequently, his condition was diagnosed as TAP in PCNSL at 2 months after onset. The patient completely recovered after treatment and experienced no recurrence of TAP for 8 months. Although it is difficult to distinguish TAP from vascular parkinsonism (VP) at initial consultation, the early diagnosis of PCNSL is important for improving prognosis. In the case of rapidly progressing parkinsonism, one should suspect the possibility of TAP associated with early-stage PCNSL. Early treatment improves the chances of remission and decreases the possibility of recurrence.

The extent of staging required to evaluate for systemic involvement in patients with primary central nervous system lymphoma (PCNSL) remains controversial. Eligible studies reporting on diagnostic yield of extensive systemic staging, including pre-treatment whole-body 18F-fluoro-deoxy-glocose positron emission tomography with or without computed tomography, in immuno-competent adults with PCNSL were identified through systematic literature search. Diagnostic yield was defined as the proportion of patients with abnormal test results outside the neuraxis that led to detection of concordant systemic high-grade lymphoma on an individual patient basis (true positives). Data were pooled using random-effects model to produce summary estimates with 95% confidence intervals (CIs). Weighted-mean pooled analysis involving 1099 patients from 14 primary studies provided an overall diagnostic yield of 6% (95% CI, 4%-8%) for extensive systemic staging in PCNSL with implications for diagnosis, prognosis, and therapy. Summary estimates of false positivity were just marginally lower at 5% (95% CI, 3%-8%) for such systemic staging.

Primary dural diffuse large B-cell lymphoma (PD-DLBCL) is a rare and aggressive B-cell non-Hodgkin lymphoma that can present in intracranial or intraspinal locations. Although the optimal management is unknown, PD-DLBCL therapy is often mirrored after primary central nervous system lymphoma therapy and aggressive treatment with a high dose methotrexate-based regimen is frequently used. Our comprehensive, retrospective study of 24 reported cases of PD-DLBCL provide the most complete analysis of this rare disease including data on biology, treatment outcomes, and survival. Our findings demonstrate good outcomes following induction treatment with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), suggesting that these cases can be treated as DLBCL rather than primary central nervous system lymphoma, obviating the need for more aggressive and toxic approaches. The durable responses following R-CHOP also confirm that PD-DLBCL is not protected by the blood brain barrier.

BACKGROUND: Primary central nervous system lymphomas (PCNSLs) account for 1%-2% of primary central nervous system tumors. Until recently, treatment has centered on biopsy, radiotherapy, and high-dose methotrexate, without a clear role for cytoreductive surgery. The objective of this article is to compare the impact of biopsy versus cytoreductive surgery in outcomes of patients with PCNSL, including postoperative complications and survival.
METHODS: We performed a systematic review of literature published from January 1, 1968 to May 2, 2018 related to PCNSL treatment in patients undergoing biopsy or resection. Data on morbidity, progression-free survival, and overall survival were extracted and analyzed.
RESULTS: A total of 1291 nonduplicate citations were identified, with 244 articles selected for full-text review. Twenty-four articles were included for data abstraction including 2 level IIb studies, 4 level IIIb studies, and the remaining 18 articles representing level IVb studies. Of these articles, 15 failed to show benefit with cytoreductive surgery; most of these articles included relatively small sample sizes and predated standardization of high-dose systemic methotrexate treatment. Larger, more recent series included 9 articles providing evidence in support of cytoreductive surgery. Patient age, functional status, and treatment with chemotherapy and/or radiation were associated with improved survival across studies.
CONCLUSIONS: The treatment of PCNSL is challenging and ever-evolving. Earlier, smaller studies failed to show the benefit of cytoreductive surgery over biopsy in patients with PCNSL. Larger, more recent series seem to show the possible benefit of cytoreductive surgery in PCNSL. Future well-designed prospective studies may help further elucidate the role of resection in the modern treatment of PCNSL.