Whole exome sequencing identifies mutational signatures of vitreoretinal lymphoma

Impact of genetic alterations on central nervous system progression of primary vitreoretinal lymphoma

Primary vitreoretinal lymphoma (PVRL) is a rare malignant lymphoma subtype with an unfavorable prognosis due to frequent central nervous system (CNS) progression. Thus, identifying factors associated with CNS progression is essential for improving the prognosis of PVRL patients. Accordingly, we conducted a comprehensive genetic analysis using archived vitreous humor samples of 36 PVRL patients diagnosed and treated at our institution and retrospectively examined the relationship between genetic alterations and CNS progression. Whole-exome sequencing (N=2) and amplicon sequencing using a custom panel of 107 lymphomagenesis-related genes (N=34) were performed to assess mutations and copy number alterations. The median number of pathogenic genetic alterations per case was 12 (range, 0-22). Pathogenic genetic alterations of CDKN2A, MYD88, CDKN2B, PRDM1, PIM1, ETV6, CD79B, and IGLL5, as well as aberrant somatic hypermutations, were frequently detected. The frequency of ETV6 loss and PRDM1 alteration (mutation and loss) was 23% and 49%, respectively. Multivariate analysis revealed ETV6 loss (hazard ratio [HR]=3.26, 95% confidence interval [CI]: 1.08-9.85) and PRDM1 alteration (HR=2.52, 95% CI: 1.03-6.16) as candidate risk factors associated with CNS progression of PVRL. Moreover, these two genetic factors defined slow-, intermediate-, and rapid-progression groups (0, 1, and 2 factors, respectively), and the median period to CNS progression differed significantly among them (52 vs. 33 vs. 20 months, respectively). Our findings suggest that genetic factors predict the CNS progression of PVRL effectively, and the genetics-based CNS progression model might lead to stratification of treatment.

Molecular Determinants of Sensitivity to Polatuzumab Vedotin in Diffuse Large B-Cell Lymphoma

Polatuzumab vedotin (Pola-V) is an antibody-drug conjugate directed to the CD79B subunit of the B-cell receptor (BCR). When combined with conventional immunochemotherapy, Pola-V improves outcomes in diffuse large B-cell lymphoma (DLBCL). To identify determinants of Pola-V sensitivity, we used CRISPR-Cas9 screening for genes that modulated Pola-V toxicity for lymphomas or the surface expression of its target, CD79B. Our results reveal the striking impact of CD79B glycosylation on Pola-V epitope availability on the lymphoma cell surface and on Pola-V toxicity. Genetic, pharmacological, and enzymatic approaches that remove sialic acid from N-linked glycans enhanced lymphoma killing by Pola-V. Pola-V toxicity was also modulated by KLHL6, an E3 ubiquitin ligase that is recurrently inactivated in germinal center derived lymphomas. We reveal how KLHL6 targets CD79B for degradation in normal and malignant germinal center B cells, thereby determining expression of the surface BCR complex. Our findings suggest precision medicine strategies to optimize Pola-V as a lymphoma therapeutic. Significance: These findings unravel the molecular basis of response heterogeneity to Pola-V and identify approaches that might be deployed therapeutically to enhance the efficacy of CD79B-specific tumor killing. In addition, they reveal a novel post-translational mechanism used by normal and malignant germinal center B cells to regulate expression of the BCR. See related commentary by Leveille, p. 1577 See related article by Meriranta et al.

Diagnostic potential of vitreoretinal lymphoma by detection of gene mutations with NGS in 25 Chinese patients

BACKGROUND

Vitreoretinal lymphoma (VRL) is a rare malignant lymphoproliferative tumor. Our study aimed to investigate the mutational profile of VRL distinguishing from uveitis using next-generation sequencing (NGS) analysis on small amounts of vitreous fluid.

METHODS

Vitreous samples from twenty-six eyes of twenty VRL patients and six eyes of five uveitis patients were enrolled. All vitreous samples underwent cytology, immunocytochemistry for B-cell markers, cytokines analysis of IL-10 and IL-6, and flow cytometry. NGS was performed in vitreous specimens from the 25 patients using 82 DLBCL-targeted mutation panels. Vitreous fluids from 8 cases were performed paired NGS-based mutation analysis on both cell-free DNA (cfDNA) and genomic DNA.

RESULTS

The sensitivity and accuracy rates for vitreous cytology were 70 % and 76 %, and for cytokine analysis (IL-10/IL-6 > 1) were 65 % and 72 %, respectively. Overall, the common mutations in VRL were PIM1 (88.5 %), IGLL5 (88.5 %), KMT2C (73 %), MYD88 (77 %), CD79B (50 %) and TBL1XR1 (46.2 %). In addition, the genetic mutation in cfDNA was consistent with that in genomic DNA in eight VRL cases.

CONCLUSIONS

The mutation analysis of 82 DLBCL-targeted spectrum mutation panels by NGS on the vitreous samples is a sensitive and specific tool for distinguishing VRL from uveitis. Utilizing cfDNA for NGS analysis may serve as a liquid biopsy to aid in the diagnosis of VRL, particularly when using small-volume aspirate.

A comprehensive overview of diagnosis, imaging and treatment of vitreoretinal lymphoma

Vitreoretinal lymphoma (VRL) is a rare B-cell intraocular neoplasia characterized by poor long-term prognosis and lack of effective therapies. It mainly involves the vitreous humor, the retina, and the retinal pigment epithelium (RPE), although anterior segment involvement can occur. VRL is classified as a lymphoma of immune privileged sites, along with testis lymphoma and primary central nervous system lymphoma (PCNSL). VRL and PCNSL are strictly connected indeed: 80% of VRL develop PCNSL, while 20% of patients with PCNSL present VRL during natural history of lymphoma. Due to the lack of worldwide consensus about diagnosis, therapy, and follow-up timing, VRL represents one of the most challenging ocular affections.VRL commonly masquerades as a posterior uveitis, and misdiagnosis often occurs because of partial response to topical steroids. Gold standard for diagnosis is cytological analysis of vitreous humor. However, this technique lacks sensitivity and supplemental molecular analyses can improve the diagnostic process. Multimodal imaging allows ophthalmologists to empower their clinical suspicion and a comprehensive examination can highlight typical features of VRL and justify further invasive procedures.There is no consensus about VRL therapy, and none of the therapeutical scheme has demonstrated to prevent cerebral involvement and improve patient's overall survival. Intravitreal injections of chemotherapeutics drugs, ocular radiation therapy and systemic chemotherapy can be considered in the treatment of VRL. Once cerebral involvement occurs, systemic chemotherapy must be included in the treatment as a life-saving therapy. Further multicentric studies are required to find out the best treatment of patients with VRL.

[Molecular diagnostics for vitreoretinal lymphoma]

Primary vitreoretinal lymphoma (PVRL) represents a subtype of intraocular lymphomas, which are a subgroup of malignant lymphomas of the eye. PVRL is considered a special form of primary diffuse large cell lymphoma (DLBCL) of the CNS (central nervous system) (PCNSL) and arises primary or secondary to PCNSL. According to the cell of origin (COO) classification of DLBCL, PVRL largely belongs to the activated B‑cell (ABC) type of DLBCL. Based on a recently established genetic-biological classification of DLBCL, PCNSL and thus also PVRL belong to a group of DLBCL of the MYD88/CD79B-mutated (MCD) or cluster 5 subtype, which often shows extranodal manifestations and MYD88 and CD79A mutations as well as CDKN2A deletions.PVRL diagnostics is often complicated as it represents a classic masquerade syndrome. Due to the usually limited material with often large numbers of reactive lymphocytes and/or degenerative changes in the cells, the results of diagnostic tests are difficult to interpret. Classic diagnostic tests include cytology on vitreous aspirates, immunocytochemistry, and clonality analysis.New insights into the spectrum of genetic alterations of vitreoretinal lymphomas (VRL) confirm the close relationship to PCNSL and could significantly improve pathological diagnosis. Next-generation sequencing panel-based diagnostics allow VRL diagnosis confirmation with little DNA in almost 100% of patients in cases with insufficient cytological evidence or lack of clonality detection. PVRL, as well as secondary vitreoretinal lymphomas after PCNSL or extracerebral DLBCL, have high mutation frequencies in characteristically mutated genes in PCNSL or MCD/cluster 5 type DLBCL. Supporting diagnostics, mutation detection can also be performed on cell-free DNA from the vitreous supernatant.

Next-Generation Sequencing of Vitreoretinal Lymphoma by Vitreous Liquid Biopsy: Diagnostic Potential and Genotype/Phenotype Correlation

Purpose

To determine the diagnostic potential of next-generation sequencing (NGS) in vitreous samples, analyze genotype-phenotype characteristics, and compare NGS of matched vitreous and brain samples in patients with associated central nervous system lymphoma (CNSL).

Methods

A total of 32 patients suspected of vitreoretinal lymphoma (VRL) who underwent diagnostic vitrectomy and NGS were included in this retrospective observational case-series. Fresh vitreous specimens from diagnostic vitrectomy of VRL-suspected patients underwent NGS using a custom panel targeting 747 candidate genes for lymphoma. They also underwent malignancy cytology, interleukin (IL)-10/IL-6, immunoglobulin heavy chain (IGH)/immunoglobulin kappa light chain (IGK) monoclonality testing. MYD88 L265P mutation was examined from anterior chamber tap samples. The diagnosis of VRL was made based on typical clinical characteristics for VRL, as well as malignant cytology, IGH/IGK clonality, or IL-10/IL-6 > 1. Sensitivity and specificity of NGS were compared with conventional diagnostic tests. Brain tissues suspected of lymphoma were collected by stereotactic biopsy and underwent NGS. Genetic variations detected in NGS of vitreous and brain tissue specimens were compared.

Results

The sensitivity values for cytology, IL-10/IL-6 > 1, clonality assays for IGH and IGK, MYD88 L265P detection in anterior chamber tap samples, and vitreous NGS were 0.23, 0.83, 0.68, 0.79, 0.67, and 0.85, with specificity values of 1.00, 0.83, 0.50, 0.25, 0.83, and 0.83, respectively. The sensitivity (0.85) of vitreous NGS was the highest compared to other conventional diagnostic tests for VRL. The most common mutations were MYD88 (91%), CDKN2A (36%), PIM1 (32%), IGLL5 (27%), and ETV6 (23%). Although several gene alterations demonstrated heterogeneity between the brain and eyes, some common mutational profiles were observed in matched vitreous and brain samples.

Conclusions

Overall, NGS of the vitreous demonstrated high sensitivity among conventional diagnostic tests. VRL and CNSL appeared to have both shared and distinct genetic variations, which may suggest site-specific variations from a common origin.

Clinical implications of circulating tumor DNA in predicting the outcome of diffuse large B cell lymphoma patients receiving first-line therapy

BACKGROUND

Circulating tumor DNA (ctDNA) has been proven to be a promising tumor-specific biomarker in solid tumors, but its clinical utility in risk stratification and early prediction of relapse for diffuse large B cell lymphoma (DLBCL) has not been well explored.

METHODS

Here, using a lymphoma-specific sequencing panel, we assessed the prognostic and predictive utilities of ctDNA measurements before, during, and after first-line therapy in 73 Chinese DLBCL patients.

RESULTS

The pretreatment ctDNA level serving as an independent prognostic factor for both progression-free survival (PFS, adjusted HR 2.47; p = 0.004) and overall survival (OS, adjusted HR 2.49; p = 0.011) was confirmed in our cohort. Furthermore, the patients classified as molecular responders who presented a larger decrease in ctDNA levels after the initial two treatment cycles had more favorable PFS (unreached vs. 6.25 months; HR 5.348; p = 0.0015) and OS (unreached vs. 25.87; HR 4.0; p = 0.028) than non-responders. In addition, interim ctDNA clearance may be an alternative noninvasive method of positron emission tomography and computed tomography (PET-CT) for predicting better PFS (HR 3.65; p = 0.0033) and OS (HR 3.536; p = 0.016). We also demonstrated that posttreatment ctDNA was a sensitive indicator for detecting minimal residual disease (MRD) in patients with a high risk of recurrence (HR 6.471; p = 0.014), who were otherwise claimed to achieve radiographic CR (complete remission).

CONCLUSIONS

CtDNA is a promising noninvasive tool for prognosis prediction, response assessment, and early relapse prediction of first-line treatment in DLBCL patients.

A Case of Spontaneous Regression and Recurrence of Primary Vitreoretinal Lymphoma

PURPOSE

To report a case of primary vitreoretinal lymphoma (PVRL) showing recurrence after spontaneous regression, diagnosed with the aid of next-generation sequencing (NGS).

METHODS

Retrospective case report.

RESULTS

A 61-year-old immunocompetent Korean woman presented with subretinal lesions suspected of PVRL, which resolved spontaneously in 2 months. After 8 months, the lesion recurred and diagnostic vitrectomy was performed. The cytologic examination of the vitreous was indeterminate as there was only minimal vitreous opacity present at the time of surgery. NGS identified significant mutations including single nucleotide variants in MYD88 L265P, which is a unique hallmark of VRL, in vitreous sample, and the diagnosis of PVRL was made.

CONCLUSION

This case showed PVRL can spontaneously regress almost completely, then recur, so careful ophthalmic and systemic follow-ups are warranted. When cytological confirmation is challenging due to the minimal disease involvement in the vitreous, NGS is effective in confirming the mutation profiles of PVRL.

Primary Vitreoretinal Lymphoma: Current Diagnostic Laboratory Tests and New Emerging Molecular Tools

Primary vitreoretinal lymphoma (PVRL), a rare aggressive malignancy primarily involving the retina and/or the vitreous, is a major diagnostic challenge for clinicians (who commonly misdiagnose it as chronic uveitis) as well as for pathologists (for biological and technical reasons). Delays in diagnosis and treatment are responsible for visual impairments and life-threatening consequences, usually related to central nervous system involvement. The identification of lymphoma cells in vitreous fluid, obtained by vitrectomy, is required for diagnosis. Of note, the scarcity of neoplastic cells in small volumes of vitreous sample, and the fragility of lymphoma cells with degenerative changes caused by previous steroid use for presumed uveitis makes diagnosis based on cytology plus immunophenotyping difficult. Interleukin levels, immunoglobulin heavy chain or T-cell receptor gene rearrangements, and MYD88 mutation are applied in combination with cytology to support diagnosis. We aim to describe the current laboratory technologies for PVRL diagnosis, focusing on the main issues that these methods have. In addition, new emerging diagnostic strategies, such as next-generation sequencing analysis, are discussed. The genetic profile of PVRL remains largely unexplored. Better knowledge of genetic alterations is critical for precision medicine interventions with target-based treatments of this lymphoma for which no standardised treatment protocol currently exists.

Update in Molecular Testing for Intraocular Lymphoma

The diagnosis of primary vitreoretinal lymphoma and central nervous system lymphoma is challenging. In cases with intraocular involvement, vitreous biopsy plays a pivotal role. Several diagnostic tests are employed to confirm a diagnosis and include cytologic evaluation, immunohistochemistry, flow cytometry, and cytokine analysis. The limitations of these conventional diagnostic tests stem from the often paucicellular nature of vitreous biopsy specimens and the fragility of malignant cells ex vivo. Several emerging molecular techniques show promise in improving the diagnostic yield of intraocular biopsy, possibly enabling more accurate and timely diagnoses. This article will review existing diagnostic modalities for intraocular lymphoma, with an emphasis on currently available molecular tests.

A pilot study of the use of dynamic analysis of cell-free DNA from aqueous humor and vitreous fluid for the diagnosis and treatment monitoring of vitreoretinal lymphomas

The diagnosis of vitreoretinal lymphoma (VRL), a rare subtype of primary central nervous system lymphoma, is challenging. We aimed to investigate the mutational landscape of VRL by sequencing circulating tumor DNA (ctDNA) from aqueous humor (AH) and/or vitreous fluid (VF), as well as applying ctDNA sequencing to diagnosis and treatment monitoring. Baseline AH and/or VF specimens from 15 VRL patients underwent comprehensive genomic profiling using targeted next-generation sequencing. The molecular profiles of paired baseline AH and VF specimens were highly concordant, with comparable allele frequencies. However, the genetic alterations detected in cerebrospinal fluid ctDNA only partially overlapped with those from simultaneously collected AH/VF samples, with much lower allele frequencies. Serial post-treatment AH or VF samples were available for five patients and their changes in ctDNA allele frequency displayed a similar trend as the changes in interleukin-10 levels; an indicator of response to treatment. A cohort of 23 patients with primary central nervous system lymphoma was included as a comparison group for the genetic landscape and evaluations of the efficacy of ibrutinib. More MYD88 mutations, but fewer IRF4 mutations and CDKN2A/B copy number losses were observed in the baseline samples of primary central nervous system lymphoma than VRL patients. The objective response rate to ibrutinib treatment was much higher for patients with primary central nervous system lymphoma (64.7%, 11/17) than for those with VRL (14.3%, 1/7). In summary, we provide valuable clinical evidence that AH is a good source of tumor genomic information and can substitute VF. Moreover, molecular profiling of AH has clinical utility for the diagnosis of VRL and treatment monitoring.

Circulating cell-free DNA and IL-10 from cerebrospinal fluids aid primary vitreoretinal lymphoma diagnosis

Primary vitreoretinal lymphoma (PVRL) is a rare variant of primary central nervous system lymphoma (PCNSL) that presents diagnostic challenges. Here, we focused on circulating cell-free DNA (cfDNA) and interleukin-10 (IL-10) isolated from cerebrospinal fluid. Twenty-three VRL patients (17 PVRL, 2 PCNSL/O, and 4 relapsed VRL, from 10/2018 to 12/2021) and 8 uveitis patients were included in this study. CSF samples from 19 vitreoretinal lymphoma patients had sufficient cfDNA for next-generation sequencing. Of these patients, 73.7% (14/19) had at least one meaningful non-Hodgkin lymphoma-related mutation. The characteristic MYD88 ^L265P mutation was detected in the CSF of 12 VRL patients, with a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 63.2%, 100%, 100%, and 46.2%, respectively. No meaningful lymphoma related mutations were found in CSF samples from uveitis controls with typical intraocular lesions. Meanwhile, CSF IL-10 levels were elevated in 95.7% of the VRL patients, with a sensitivity, specificity, PPV, and NPV of 95.7%, 100%, 100% and 88.9%, respectively. Key somatic mutations like MYD88 ^L265P and CD79B detected from CSF cfDNA and elevated CSF IL-10 levels can be promising adjuncts for primary vitreoretinal lymphoma diagnosis.

Cell-Free DNA Sequencing of Intraocular Fluid as Liquid Biopsy in the Diagnosis of Vitreoretinal Lymphoma

Purpose

To seek novel diagnostic approaches, we improved the workflow of cell-free DNA (cfDNA) sequencing and evaluated its feasibility in vitreoretinal lymphoma (VRL) specimens; the profile of mutations was preliminarily analyzed for potential diagnostic value.

Methods

The study was a diagnostic trial. 23 eyes of 23 patients with VRL and 25 eyes of 25 patients with inflammatory eye diseases were enrolled. Approximate 500μl undiluted vitreous humor and 10ml diluted vitreous fluid was obtained through diagnostic vitrectomy and sent for cytopathological examinations. 500μl of the diluted vitreous fluid was spared for cfDNA sequencing. For cfDNA sequencing, DNA fragmentation procedure was added to the workflow to improve the extraction efficiency; mutations detected were analyzed for potential diagnostic model. The sensitivity and specificity of the cytopathology and cfDNA sequencing were compared. The clinical manifestations were preliminarily analyzed for potential correlations with the genotypes.

Results

CfDNA sequencing was accomplished in 23 eyes with VRL and 20 eyes with inflammatory eye diseases. VRL-related mutated genes included MYD88 (18 eyes, 78%), ETV6 (11 eyes, 48%), PIM1 (11 eyes,48%), BTG2 (7 eyes, 30%), IRF4 (7 eyes, 30%), CD79B (6 eyes, 26%), LRP1B (6 eyes, 26%), etc. Logistic regression based on the mutations of MYD88 and ETV6 was of the potential for the diagnosis of VRL (P<0.001, adjusted R2 = 0.789, sensitivity 0.913, specificity 0.950); by comparison, the sensitivity and specificity of the vitreous cytopathology were 0.826 and 1.000, respectively. Further analysis of the mutation profile showed that patients carrying CD79B mutation tended to have higher intraocular interleukin-10 level (P=0.030), that CARD11 mutation was correlated with younger age at ocular onset (P=0.039), and that patients with intracranial involvement carried more multiple-site mutations in the BTG2 gene (P=0.013).

Conclusions

The improved workflow of CfDNA sequencing is of sound feasibility in a limited amount of vitreous humor. The logistic model based on the mutations could help to provide reliable clues for the diagnosis of VRL.

[Lymphoma of the eye and its adnexa : Modern pathological diagnostics and systemic treatment]

BACKGROUND

Malignant lymphomas of the eye and its adnexal structures account for approximately 5-15% of extranodal lymphomas. According to anatomic and biological criteria, two large groups of lymphomas in and around the eye need to be distinguished: (1) primary lymphomas of intraocular structures and (2) primary lymphomas of ocular adnexa. Furthermore, there is a large spectrum of secondary manifestations of malignant lymphomas in ocular and periocular structures.

OBJECTIVE

This article gives a summary of the classification and molecular pathology of various intraocular and periocular lymphomas as well as oncological systemic treatment with a focus on primary vitreoretinal lymphomas.

METHODS

A selective literature search was carried out in PubMed on the topic of intraocular and periocular lymphomas and own experiences are presented.

RESULTS

The treatment of primary vitreoretinal lymphomas (PVRL) is an interdisciplinary challenge and despite the apparently localized disease, systemic treatment concepts are necessary to reduce the high risk of secondary involvement of the central nervous system (CNS). Therefore, it is crucial that the substances used can penetrate the CNS, and protocols should be chosen in accordance with the treatment concepts for primary CNS lymphomas. The knowledge on the genetics and biology of ocular lymphomas generated by modern high throughput methods enable not only improved diagnostics using molecular methods but also provide rationales for targeted therapeutic approaches.

CONCLUSION

A deep understanding of the biological and molecular principles of intraocular and periocular lymphomas forms a basic prerequisite for precise diagnostics and the use of targeted systemic treatment.

The molecular hallmarks of primary and secondary vitreoretinal lymphoma

Vitreoretinal lymphoma (VRL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL) considered a variant of primary central nervous system lymphoma (PCNSL). The diagnosis of VRL requires examination of vitreous fluid, but cytologic differentiation from uveitis remains difficult. Because of its rarity and the difficulty in obtaining diagnostic material, little is known about the genetic profile of VRL. The purpose of our study was to investigate the mutational profile of a large series of primary and secondary VRL. Targeted next-generation sequencing using a custom panel containing the most frequent mutations in PCNSL was performed on 34 vitrectomy samples from 31 patients with VRL and negative controls with uveitis. In a subset of cases, genome-wide copy number alterations (CNAs) were assessed using the OncoScan platform. Mutations in MYD88 (74%), PIM1 (71%), CD79B (55%), IGLL5 (52%), TBL1XR1 (48%), ETV6 (45%), and 9p21/CDKN2A deletions (75%) were the most common alterations, with similar frequencies in primary (n = 16), synchronous (n = 3), or secondary (n = 12) VRL. This mutational spectrum is similar to MYD88mut/CD79Bmut (MCD or cluster 5) DLBCL with activation of Toll-like and B-cell receptor pathways and CDKN2A loss, confirming their close relationship. OncoScan analysis demonstrated a high number of CNAs (mean 18.6 per case). Negative controls lacked mutations or CNAs. Using cell-free DNA of vitreous fluid supernatant, mutations present in cellular DNA were reliably detected in all cases examined. Mutational analysis is a highly sensitive and specific tool for the diagnosis of VRL and can also be applied successfully to cell-free DNA derived from the vitreous.

Diagnosing Vitreoretinal Lymphomas-An Analysis of the Sensitivity of Existing Tools

Simple Summary

Diagnostics of vitreoretinal lymphoma is very challenging, as the possibility of receiving false negative results is common. We retrospectively analyzed the sensitivity of the most commonly used diagnostic methods including ancillary immunohistochemistry, Myeloid Differentiation Factor 88 (MyD88) L256P mutation analysis, polymerase chain reaction (PCR) for monoclonal rearrangements of immunoglobulin heavy chain (IgH) and T-cell Receptor (TCR) genes, flow cytometry, and IL10 and IL6 analysis, to diagnose vitreoretinal lymphomas from published data in the literature. MyD88 mutation analysis caused by a hotspot mutation in MyD88 was the most sensitive and had the lowest coefficient of variation.

Abstract

Vitreoretinal lymphoma (VRL) is a rare ocular pathology that is notorious for mimicking chronic uveitis, which is a seemingly benign condition in comparison. The most common form of VRL is the diffuse large B-cell type, and there has been a high mortality rate. This dismal prognosis can be improved significantly if the disease is diagnosed early, but until now there is no consensus on an appropriate diagnostic algorithm. We conducted a retrospective search of PubMed Central^® and analyzed results from thirty-three studies that were published between 2011–2021. The chosen studies incorporated some popular testing tools for VRL, and our analyses focused on comparing the average sensitivity of five diagnostic methods. The methods included cytology including ancillary immunohistochemistry, Myeloid Differentiation Factor 88 (MyD88) mutation analysis, polymerase chain reaction (PCR) for monoclonal rearrangements of immunoglobulin heavy chain (IgH) and T-cell Receptor (TCR) genes, flow cytometry, and IL10 and IL6 analysis. Across the varied diagnostic methods employed in thirty-three studies explored in this analysis, MyD88 mutation assay emerged as a strong contender given its sensitivity and low coefficient of variation. There is an imminent need for the introduction of newer assays that can further improve the sensitivity of identifying MyD88 mutation in cancer cells seen in the vitreous.

Update on Novel Therapeutics for Primary CNS Lymphoma

Simple Summary

Primary central nervous system lymphoma is a rare and aggressive form of non-Hodgkin lymphoma. While it is highly responsive to first-line chemo and radiation treatments, rates of relapse are high, demonstrating the need for improved therapeutic strategies. Recent advancements in the understanding of the pathophysiology of this disease have led to the identification of new potential treatment targets and the development of novel agents. This review aims to discuss different targeted strategies and review some of the data supporting these approaches, and discusses recently completed and ongoing clinical trials using these novel agents.

Abstract

Primary central nervous system lymphoma (PCNSL) is a rare lymphoma isolated to the central nervous system or vitreoretinal space. Standard treatment consists of cytotoxic methotrexate-based chemotherapy, with or without radiation. Despite high rates of response, relapse is common, highlighting the need for novel therapeutic approaches. Recent advances in the understanding of PCNSL have elucidated mechanisms of pathogenesis and resistance including activation of the B-cell receptor and mammalian target of rapamycin pathways. Novel treatment strategies such as the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, phosphatidylinositol-3 kinase (PI3K) inhibitors, and immunomodulatory drugs are promising. Increasingly, evidence suggests immune evasion plays a role in PCNSL pathogenesis and several immunotherapeutic strategies including checkpoint inhibition and targeted chimeric antigen receptor T (CAR-T) cells are under investigation. This review provides a discussion on the challenges in development of targeted therapeutic strategies, an update on recent treatment advances, and offers a look toward ongoing clinical studies.

Vitreoretinal Lymphoma

Vitreoretinal lymphoma (VRL) is a rare variant of primary central nervous system lymphoma (PCNSL), mostly of diffuse large B cell lymphoma, which affects the retina and/or the vitreous with or without optic nerve involvement. The disease course is aggressive. Up to 90% of the patients develop central nervous system lymphoma within one year. The diagnosis of VRL is challenging due to nonspecific chronic and relapsing uveitis and is made by anterior chamber tab or vitreous aspirate biopsy. There is no established treatment protocol for VRL patients with bilateral involvement without CNS involvement. There are suggestions to use only intravitreal chemotherapy with methotrexate and/or rituximab. Alternatively, systemic high-dose MTX treatment or external beam radiotherapy is used. Further studies are needed to prove and confirm the prophylactic systemic therapy in preventing CNS involvement in limited VRL.

Primary vitreoretinal lymphoma: A diagnostic and management challenge

Primary vitreoretinal lymphoma (PVRL) is a rare form of primary central nervous system lymphoma (PCNSL) arising in the intraocular compartment without brain involvement. Despite its apparent indolent clinical course, PVRL can cause permanent vision loss and CNS relapse, the major cause of death in PVRL patients. The pathophysiology of PVRL is unknown. As in PCNSL, the transformation of the tumor cells likely originates outside the CNS, before the cells migrate to the eye and proliferate within an immune-permissive microenvironment. PVRL exhibits a biased immunoglobulin repertoire, suggesting underlying antigen selection. The diagnosis remains challenging, requiring close coordination between ophthalmologists and cytologists. Because of their rarity and fragility in the vitreous, lymphoma cells cannot always be identified. Interleukin levels, molecular biology and imaging are used in combination with clinical ophthalmological examination to support the diagnosis of PVRL. Multi-institutional prospective studies are urgently needed to validate the equivocal conclusions regarding treatments drawn from heterogeneous retrospective or small cohort studies. Intravitreal injections of methotrexate or rituximab or local radiotherapy are effective at clearing tumor cells within the eyes but do not prevent CNS relapse. Systemic treatment based on high-dose methotrexate chemotherapy, with or without local treatment, might reduce this risk. At relapse, intensive consolidation chemotherapy followed by stem cell transplantation can be considered. Single-agent ibrutinib, lenalidomide and temozolomide treatments are effective in patients with relapsed PVRL and should be tested as first-line treatments. Therapeutic response assessment based on a clinical examination is improved by measuring cytokine levels but still needs to be refined.

Serial Detection of MYD88 L265P Mutation in the Aqueous Humor of a Patient with Vitreoretinal Lymphoma for Disease Monitoring

PURPOSE

To report a case of a patient whose MYD88 mutation disappeared from the aqueous humor following treatment with intravitreal methotrexate.

METHODS

A retrospective review of clinical, histopathological and imaging records.

RESULTS

A 49-year-old woman presented with bilateral primary vitreoretinal lymphoma confirmed by molecular and next-generation sequencing studies on vitreous biopsy samples. Initially, the MYD88 L265P mutation was detected in aqueous samples of both eyes. Serial testing for MYD88 L265P mutations performed on aqueous samples collected at the time of the weekly intravitreal methotrexate injections showed the mutation ceased to be detected after four weekly injections in the non-vitrectomized right eye and after two weekly injections in the vitrectomized left eye. Clinical improvement accompanied the negativization of the mutation in both eyes.

CONCLUSION

We present a case that demonstrates the possible utilization of serial testing for the MYD88 L265P mutation as a tool for monitoring disease course in vitreoretinal lymphoma.