Cytologic and Molecular Diagnostics for Vitreoretinal Lymphoma: Current Approaches and Emerging Single-Cell Analyses

A six-year comprehensive review of eye cytology cases received at a tertiary level hospital

BACKGROUND

Ocular cytology is an effective method of diagnosing infective, benign, and malignant ocular disease processes due to easy accessibility and rapid turnaround time. However, these specimens pose significant diagnostic challenges due to rarity of the specimen type, sparse diagnostic material available for ancillary workup, and unfamiliarity of the diagnostic entities by the cytopathologist.

METHODS

This study conducted a 6-year comprehensive review of 65 eye cytology cases received at a tertiary level hospital. Cytopathologic diagnoses of "negative for malignancy" and "atypical" were categorized as negative findings (70.8%, n = 46) and diagnoses of "suspicious for malignancy" and "positive for malignancy" were categorized as positive findings (23.1%, n = 15). A 44.6% (n = 29) of cases had subsequent histopathology and/or flow cytometry diagnoses. Premalignant and malignant lesions detected on histopathology were considered as significant findings. Statistical analysis was performed to evaluate the concordance of ocular cytology with associated histopathology and/or flow cytometry diagnoses.

RESULTS

The accuracy of final cytology-histopathology and/or cytology-flow cytometry diagnoses in this cohort of cases is 86.2%. The sensitivity and specificity of ocular diagnosis by cytology are 66.6% and 100%, respectively. The positive and negative predictive values of ocular diagnosis by cytology are 100% and 80.9%, respectively.

CONCLUSION

Ocular cytology is a fast, effective, and sensitive method for diagnosing ocular pathology specimens. Familiarity with these specimen types by cytopathologists can help in diagnosing ocular diseases effectively on small, challenging cytologic preparations.

Refractory Primary Vitreoretinal Lymphoma Involving the Spinal Cord with a Temporary Complete Response to Tirabrutinib

Many patients with primary vitreoretinal lymphoma (PVRL) exhibit central nervous system (CNS) involvement either at the diagnosis or during follow-up. The prognosis in the patients of PVRL with relapsed or refractory CNS remains extremely poor. We herein report a patient with refractory PVRL who had recurrence in the spinal cord despite receiving high-dose methotrexate-based chemotherapy and whole-brain radiotherapy. The patient surprisingly responded to tirabrutinib temporarily. We believe that this case suggests the utility of this new target therapy.

Diagnostic Confirmation of Choroidal Lymphoma by Anterior Chamber Paracentesis and Aqueous Fluid Flow Cytometry

PURPOSE

To report the clinical course of patients with diagnostic confirmation of choroidal lymphoma by anterior chamber paracentesis and aqueous fluid flow cytometry.

METHODS

Single-center case series.

RESULTS

Two patients with choroidal thickening were suspected to have choroidal lymphoma based on clinical findings and ultrasonographic evidence of extrascleral extension. In each case, anterior chamber paracentesis was performed due to the observation of the associated anterior chamber reaction. Flow cytometry detected the presence of a clonal B-cell population consistent with non-Hodgkin's lymphoma. In one case, external beam radiation therapy resulted in a complete therapeutic response. More invasive methods of ocular tissue biopsy were avoided.

CONCLUSIONS

Definitive diagnosis in suspected cases of choroidal lymphoma remains challenging. Ocular fluid sampling may be a low morbidity and convenient alternative for confirming a suspected diagnosis in cases associated with cellular infiltration of the intraocular fluids.

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.

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.