Ocular adnexal marginal zone lymphoma of mucosa-associated lymphoid tissue

Declining incidence and improving survival of ocular and orbital lymphomas in the US between 1995 and 2018

This epidemiological study examined ocular and orbital lymphomas in the United States from 1995 to 2018, using data from the North American Association of Central Cancer Registries database of 87,543 patients with ocular and adnexal malignancies. We identified 17,878 patients (20.4%) with ocular and orbital lymphomas, with an age-standardized incidence rate (ASIR) of 2.6 persons per million (ppm). The incidence was the highest in the orbit (ASIR = 1.24), followed by the conjunctiva (ASIR = 0.57). Non-Hodgkin B-cell lymphoma was the most prevalent subtype (85.4%), particularly marginal-zone lymphoma (45.7%). Racial disparities were noted, with Asia-Pacific Islanders showing the highest incidence (orbit, 1.3 ppm). The incidence increased significantly from 1995 to 2003 (Average Percent Change, APC = 2.1%) but declined thereafter until 2018 (APC = - 0.7%). 5-year relative survival (RS) rates varied, with the highest rate for conjunctival lymphoma (100%) and the lowest for intraocular lymphoma (70.6%). Survival rates have generally improved, with an annual increase in the 5-year RS of 0.45%. This study highlights the changing epidemiological landscape, pointing to initial increases and subsequent decreases in incidence until 2003, with survival improvements likely due to advancements in treatment. These findings underscore the need for further research to investigate the root causes of these shifts and the declining incidence of ocular lymphoma.

Predicting the risk of distant and local recurrence for patients with ocular adnexal extranodal marginal zone lymphoma: a matched case-control study

BACKGROUND/AIMS

Extranodal marginal zone lymphoma of ocular adnexa (OA-EMZL) is the most frequent type of ocular adnexal lymphomas, with a high rate of disease recurrence. Precise patient stratification based on disease recurrence is understudied. This study aims to identify risk factors of distant recurrence (DR) and local recurrence (LR) to construct a prognostic model optimising rapid decision of therapeutic strategies.

METHODS

A total of 104 patients diagnosed with OA-EMZL between January 2011 and February 2020 were enrolled. Propensity score matching was performed for DR and LR groups. A nomogram was generated using a multivariate Cox proportional hazards model.

RESULTS

After matching, different independent risk factors of DR and LR were identified. Monocyte percentage (p=0.015) and M category >0 (p=0.043) were significant independent risk factors of DR. Epiphora (p<0.001) was the significant independent risk factor of LR. Three factors (monocyte percentage, M category >0, age >60) were integrated into the nomogram to predict the risk of DR. It had a relatively better discriminative ability for distant recurrence-free survival (C-index: 3-year, 0.784; 6-year, 0.801) than IPI score (C-index: 3-year, 0.663; 6-year, 0.673) in the cohort of all patients.

CONCLUSION

Our analyses suggested DR and LR as two distinct prognostic events, and additionally identified novel risk factors of them. The nomogram may serve as a practical tool for the prognostic estimation and rapid decision of therapeutic strategies for patients with OA-EMZL.

Signaling pathways driving ocular malignancies and their targeting by bioactive phytochemicals

Ocular cancers represent a rare pathology. The American Cancer Society estimates that 3,360 cases of ocular cancer occur annually in the United States. The major types of cancers of the eye include ocular melanoma (also known as uveal melanoma), ocular lymphoma, retinoblastoma, and squamous cell carcinoma. While uveal melanoma is one of the primary intraocular cancers with the highest occurrence in adults, retinoblastoma remains the most common primary intraocular cancer in children, and squamous cell carcinoma presents as the most common conjunctival cancer. The pathophysiology of these diseases involves specific cell signaling pathways. Oncogene mutations, tumor suppressor mutations, chromosome deletions/translocations and altered proteins are all described as causal events in developing ocular cancer. Without proper identification and treatment of these cancers, vision loss, cancer spread, and even death can occur. The current treatments for these cancers involve enucleation, radiation, excision, laser treatment, cryotherapy, immunotherapy, and chemotherapy. These treatments present a significant burden to the patient that includes a possible loss of vision and a myriad of side effects. Therefore, alternatives to traditional therapy are urgently needed. Intercepting the signaling pathways for these cancers with the use of naturally occurring phytochemicals could be a way to relieve both cancer burden and perhaps even prevent cancer occurrence. This research aims to present a comprehensive review of the signaling pathways involved in various ocular cancers, discuss current therapeutic options, and examine the potential of bioactive phytocompounds in the prevention and targeted treatment of ocular neoplasms. The current limitations, challenges, pitfalls, and future research directions are also discussed.

Clinical characteristics and treatment outcomes of secondary ocular adnexal lymphoma

BACKGROUND

To describe the clinical characteristics and treatment outcomes of secondary ocular adnexal lymphoma (OAL), and emphasise the impact of timely biopsy and systemic evaluation on the diagnosis and treatment.

METHODS

The data of patients with secondary OAL in our hospital from January 2010 to June 2021 were retrospectively reviewed.

RESULTS

A total of 54 patients (30 men and 24 women) were included in the study. The mean age at presentation was 60 years (median 62 years; range 37-83 years). The main symptoms included ocular mass (74%), periorbital swelling (43%), and proptosis (39%). The main histopathological types were mucosa-associated lymphoid tissue lymphoma (30%), diffuse large B-cell lymphoma (28%), and natural killer/T-cell lymphoma (18%). In particular, three patients exhibited different pathological types of ocular lymphoma compared to previously diagnosed systemic lymphoma. The most common site of ocular and systemic involvement was the orbit (85%) and lymph nodes (56%), respectively, and 25 (46%) patients had occult extraocular lesions. Additionally, the 5-year overall survival rate of the entire cohort was 56%, and significant differences were observed between the three main pathological types and stages of the disease (all p < 0.001).

CONCLUSIONS

Secondary OAL is a rare disease with a poor prognosis. That the disease is associated with a more aggressive pathological type is well established, indolent lymphoma is not uncommon. Furthermore, OAL and previously diagnosed systemic lymphoma may be pathologically distinct in some patients. Therefore, we recommend a prompt excision biopsy and a thorough systemic evaluation of patients with suspected OAL.

Proteotranscriptomics of ocular adnexal B-cell lymphoma reveals an oncogenic role of alternative splicing and identifies a diagnostic marker

Background

Ocular adnexal B-cell lymphoma (OABL) is a rare subtype of non-Hodgkin lymphoma. The molecular characteristics of OABL remain poorly understood. We performed an integrated study to investigate the proteotranscriptome landscape and identify novel molecular characteristics and biomarkers of OABL.

Methods

Integrated quantitative proteome and transcriptome were performed on 40 OABL 12 idiopathic orbital inflammation, 6 reactive lymphoid hyperplasia, and 13 aesthetic orbital plastic surgery specimens. Complete clinicopathologic and prognostic data of the patients were recorded.

Results

We identified high global protein-mRNA concordance as a novel characteristic of OABL. High concordance was related to OABL recurrence. By integrated expression profile, motif enrichment and trend analysis, we found that alternative splicing is inflammation-independently dysregulated in OABL. After portraying the aberrant alternative splicing event landscape, we demonstrated the oncogenic role of ADAR, a core splicing regulator that regulates the splicing of Rho GTPase and cell cycle members. We found that ADAR regulates cell proliferation and Rho GTPase inhibitor sensitivity of lymphoma. We identified DNAJC9 as a potential biomarker for OABL in proteomic analyses. Immunohistochemistry and immunofluorescent staining showed the nuclear staining of DNAJC9 was significantly higher in extranodal marginal zone lymphomas compared with inflammation specimens.

Conclusions

These results provide an integrated gene expression profiling and demonstrate that high global protein-mRNA concordance is a prognosis-related molecular characteristic of OABL. We portray the alternative splicing events landscape of OABL, and reveal the oncogenic role of ADAR. We identified strong nuclear staining of DNAJC9 as a promising pathology diagnostic biomarker for extranodal marginal zone lymphomas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02445-8.

Radiation therapy for primary orbital and ocular adnexal lymphoma

OBJECTIVE

To report the efficacy and toxicity of External beam Radiotherapy (EBRT) as a sole treatment for MALT and Follicular Primary Orbital and Ocular adnexal Lymphoma (POOAL).

METHODS

Retrospective review of all POOAL patients treated with EBRT utilizing megavoltage photon or electron beam radiotherapy between 2003 and 2015. Patient demographics, tumour extent and pathology, radiotherapy techniques, and treatment outcomes were reviewed. The actuarial rates of tumour control and radiation toxicities were calculated using Kaplan-Meier estimates.

RESULTS

This study included 167 tumours, of which MALT lymphoma involved 149 (89 %). The conjunctiva and orbit were equally involved as the predominant site (48 %). Megavoltage photon radiotherapy was used in 60 % of predominantly orbital lymphoma and Electron beam with lens shielding in 77 % of the conjunctival lymphoma. The majority (95 %) were treated with a total dose of 25 Gy in 10 fractions. Local control rate was 98 % (CI: 93-100 %) at 5 years. The long-term RT toxicities included dry eye in 27 eyes (16 %) and cataract in 22 (13 %). None of the patients developed significant structural or functional radiation toxicity.

CONCLUSION

External Beam Radiotherapy, with lens shielding whenever indicated, at a dose of 20-30 Gy delivered over 10-20 fractions is an efficacious and safe primary treatment option for POOAL lymphoma, with excellent local control and low incidence of late manageable ocular toxicities.

A deep learning model combining multimodal radiomics, clinical and imaging features for differentiating ocular adnexal lymphoma from idiopathic orbital inflammation

OBJECTIVES

To evaluate the value of deep learning (DL) combining multimodal radiomics and clinical and imaging features for differentiating ocular adnexal lymphoma (OAL) from idiopathic orbital inflammation (IOI).

METHODS

Eighty-nine patients with histopathologically confirmed OAL (n = 39) and IOI (n = 50) were divided into training and validation groups. Convolutional neural networks and multimodal fusion layers were used to extract multimodal radiomics features from the T1-weighted image (T1WI), T2-weighted image, and contrast-enhanced T1WI. These multimodal radiomics features were then combined with clinical and imaging features and used together to differentiate between OAL and IOI. The area under the curve (AUC) was used to evaluate DL models with different features under five-fold cross-validation. The Student t-test, chi-squared, or Fisher exact test was used for comparison of different groups.

RESULTS

In the validation group, the diagnostic AUC of the DL model using combined features was 0.953 (95% CI, 0.895-1.000), higher than that of the DL model using multimodal radiomics features (0.843, 95% CI, 0.786-0.898, p < 0.01) or clinical and imaging features only (0.882, 95% CI, 0.782-0.982, p = 0.13). The DL model built on multimodal radiomics features outperformed those built on most bimodalities and unimodalities (p < 0.05). In addition, the DL-based analysis with the orbital cone area (covering both the orbital mass and surrounding tissues) was superior to that with the region of interest (ROI) covering only the mass area, although the difference was not significant (p = 0.33).

CONCLUSIONS

DL-based analysis that combines multimodal radiomics features with clinical and imaging features may help to differentiate between OAL and IOI.

KEY POINTS

• It is difficult to differentiate OAL from IOI due to the overlap in clinical and imaging manifestations. • Radiomics has shown potential for noninvasive diagnosis of different orbital lymphoproliferative disorders. • DL-based analysis combining radiomics and imaging and clinical features may help the differentiation between OAL and IOI.

The Biology of Ocular Adnexal Marginal Zone Lymphomas

This review focuses on the biology of ocular adnexal marginal zone B-cell lymphomas of the mucosa-associated lymphatic tissue (MALT) (OAMZL) subtype. The ocular adnexa includes all structures and tissues within the orbit except for the eye bulb. In the region of the ocular adnexa, MALT lymphomas represent the most common subtype of lymphoma, accounting for around 8% of all non-Hodgkin lymphomas. These lymphomas are often preceded by inflammatory precursor lesions. Either autoantigens or infectious antigens may lead to disease development by functioning as continuous antigenic triggers. This triggering leads to a constitutive activation of the NF-κB signaling pathway. The role of antigenic stimulation in the pathogenesis of OAMZL is supported by the detection of somatic mutations (partially with further intraclonal diversity) in their rearranged immunoglobulin V genes; hence, their derivation from germinal-center-experienced B cells, by a restricted IGHV gene usage, and the validation of autoreactivity of the antibodies in selected cases. In the established lymphomas, NF-κB activity is further enforced by mutations in various genes regulating NF-κB activity (e.g., TNFAIP3, MYD88), as well as recurrent chromosomal translocations affecting NF-κB pathway components in a subset of cases. Further pathogenetic mechanisms include mutations in genes of the NOTCH pathway, and of epigenetic regulators. While gene expression and sequencing studies are available, the role of differential methylation of lymphoma cells, the role of micro-RNAs, and the contribution of the microenvironment remain largely unexplored.

Vitreoretinal lymphoma occurring after systemic chemotherapy for primary conjunctival diffuse large B cell lymphoma: A case report

INTRODUCTION

Ocular adnexal lymphoma and vitreoretinal lymphoma are rare forms of non-Hodgkin lymphoma. They are regarded as distinct disease entities due to the differences in molecular mechanism, management, and outcome. We present a rare case of conjunctival diffuse large B cell lymphoma (DLBCL) that developed to vitreoretinal lymphoma after systemic chemotherapy.

PATIENT CONCERNS

A 60-year-old man presented with a left salmon-colored conjunctival mass.

DIAGNOSIS

A biopsy was performed, and histopathologic examination showed DLBCL. Immunohistochemical staining was positive for CD20 with increased κ to λ light chain ratio.

INTERVENTIONS

Bone marrow biopsy also revealed DLBCL. Gallium-67 scintigraphy showed abnormal uptake only in the left orbital lesion. Ann Arbor stage was estimated as IV. The patient underwent systemic combination chemotherapy and immunotherapy.

OUTCOMES

Four months after the last course of chemotherapy, primary conjunctival DLBCL relapsed, manifesting vitreous opacity. Diagnostic vitrectomy confirmed a diagnosis of vitreoretinal lymphoma.

LESSONS

Conjunctival DLBCL and vitreoretinal lymphoma are both DLBCL. After systemic chemotherapy for conjunctival DLBCL, the lymphoma may relapse in intraocular sites as secondary vitreoretinal lymphoma.

Ten-year epidemiological study of ocular and orbital tumors in Chiba University Hospital

Background

The purpose of this study is to determine the epidemiology of tumors of the ocular adnexa and orbit in Japan.

Methods

We conducted a retrospective study on the histopathological reports in the medical records of the Chiba University Hospital from April 2009 to March 2019. Three hundred and seventy two records were examined. In addition, we examined the annual changes in the major types of tumors including malignant lymphomas and IgG4-related diseases (IgG4-RDs).

Results

There were 270 conjunctival or eyelid tumors with 166 benign and 104 malignant. There were 102 orbital tumors with 55 benign, 47 malignant tumors, and 21 cases of IgG4-RDs. Ten cases of adenoma (2.7%), another benign tumor, was also diagnosed. The major malignant tumors were malignant lymphoma in 74 cases, sebaceous gland carcinoma (SGC) in 28 cases, basal cell carcinoma in 15 cases, and squamous cell carcinoma in 8 cases. The SGCs were the most common malignant eyelid tumor at 54%. Among the malignant lymphomas, extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue type, MALT lymphomas, was the most common at 51 cases and the second most common was the diffuse large B-cell lymphoma at 11 cases. The ratio of MALT lymphomas to that of all malignant lymphomas increased significantly with years. The serum IgG4 values were measured more often in the last 5 years (70%) than in the former 5 years (33%).

Conclusions

We conclude that malignant lymphoma is a major malignant tumor in Japan and pathological biopsies should be done proactively to prevent missing IgG4-positive MALT lymphomas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02108-w.

Bacterial Infection and Non-Hodgkin B-Cell Lymphoma: Interactions between Pathogen, Host and the Tumor Environment

Non-Hodgkin B-cell lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms with complex etiopathology, rich symptomatology, and a variety of clinical courses, therefore requiring different therapeutic approaches. The hypothesis that an infectious agent may initiate chronic inflammation and facilitate B lymphocyte transformation and lymphogenesis has been raised in recent years. Viruses, like EBV, HTLV-1, HIV, HCV and parasites, like Plasmodium falciparum, have been linked to the development of lymphomas. The association of chronic Helicobacter pylori (H. pylori) infection with mucosa-associated lymphoid tissue (MALT) lymphoma, Borrelia burgdorferi with cutaneous MALT lymphoma and Chlamydophila psittaci with ocular adnexal MALT lymphoma is well documented. Recent studies have indicated that other infectious agents may also be relevant in B-cell lymphogenesis such as Coxiella burnettii, Campylobacter jejuni, Achromobacter xylosoxidans, and Escherichia coli. The aim of the present review is to provide a summary of the current literature on infectious bacterial agents associated with B-cell NHL and to discuss its role in lymphogenesis, taking into account the interaction between infectious agents, host factors, and the tumor environment.

Clinical Features and Prognoses of IgG4-Positive and IgG4-Negative Lacrimal Lymphomas

Purpose: The clinical characteristics and prognoses of immunoglobulin G4-positive (IgG4+) and IgG4-negative (IgG4−) lacrimal lymphomas were comparatively analyzed to screen for clinical indicators with differential diagnostic significance.

Methods: This was a retrospective and single-center clinical study. From June 2011 to June 2018, clinical data of 39 patients with lacrimal lymphoma, diagnosed by histopathology were collected from the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University.

Results: According to inclusion and exclusion criteria, 30 (76.9%) were in the IgG4− group and 9 (23.1%) were in the IgG4+ group. In the IgG4+ group, the sex ratio of male to female was 2:1 and the mean age was 56.67 ± 13.29 years old. In the IgG4− group, the sex ratio of male to female was 3.29:1 and the mean age was 61.47 ± 12.87 years old. Statistical analysis of the clinical indicators showed significant differences between the two groups in affected eye, preoperative history of glucocorticoids, ocular nerve thickening, the expression of serum IgG4 and prognosis (P < 0.05). There was no significant statistical difference in laboratory indicators between the two groups, including C3, C4, RF, ASO, CRP, IgA, IgM, IgG, IgG1, IgG2, and IgG3 (P > 0.05). The event-free cumulative percentages at 3 and 5 years for the 39 lacrimal lymphomas were 81.1 and 62.4%, respectively, with recurrence and death as end events. In 34 lacrimal gland MALT lymphoma cases, the event-free cumulative percentages at 3 and 5 years were 84.4 and 69.1%, respectively. In the IgG4+ and IgG4− groups, the event-free cumulative percentages at 3 years were 75.0 and 87.7%, respectively. The event-free cumulative percentage at 5 years was 62.6% in the IgG4-group and insignificant in the IgG4+ group. There was no statistical difference in event-free cumulative percentage between the two groups (P = 0.983).

Conclusion: The pathogenesis and disease characteristics of IgG4-positive lacrimal lymphoma may differ from IgG4-negative lacrimal lymphoma, but the positive expression of IgG4 may not have significant influence on the recurrence of lacrimal lymphoma.

Ocular adnexal lymphoma in Denmark: a nationwide study of 387 cases from 1980 to 2017

BACKGROUND

Nationwide studies of ocular adnexal lymphoma (OAL) are very rare in the literature, and knowledge on incidence, subtype distribution and long-term survival data is limited. This is the largest national study of OAL to date. This study sought to find information on incidence, changes in incidence, clinical findings, distribution of subtypes, survival and prognostic factors.

METHODS

Patients diagnosed with OAL from January 1, 1980 to December 31, 2017 were identified in Danish registers, and clinical as well as survival data were collected. The data were analysed with Kaplan-Meier plots and log-rank test.

RESULTS

387 patients were included in the study. The major lymphoma subtypes were extranodal marginal-zone B cell lymphoma (EMZL) (55%), diffuse large B cell lymphoma (DLBCL) (13%), mantle cell lymphoma (MCL) (11%) and follicular lymphoma (FL) (10%). OAL is a disease of the elderly (median age 69 years). The incidence of lymphoma of the ocular adnexal region has increased significantly throughout the time period of the study (Pearson correlation coefficient, r=0.65; P<0.001). In the period 1980-1984, the incidence was 0.086 per 100 000, which increased to 0.307 per 100 000 in the period 2013-2017. Low-grade, low-stage primary lymphomas were treated with radiotherapy, whereas patients with high-stage, high-grade and/or relapsed disease were treated with chemotherapy. Low-grade subtypes EMZL (89%) and FL (56%) had better 10-year disease-specific survival than the high-grade lymphomas DLBCL (38%) and MCL (31%)(p<0.001).

CONCLUSION

OAL is increasing in incidence in the Danish population for unknown reasons. However, the prognosis for most OAL is favourable, as highlighted in this national long-term study.

Involvement of Helicobacter Pylori in Ocular Adnexa Lymphoma

Helicobacter pylori has been proposed as a possible etiologic factor of ocular adnexa lymphoma (OAL), although with conflicting results. To assess the involvement of H. pylori in OAL, as (1) H. pylori DNA positivity on OAL specimens, and (2) prevalence of H. pylori gastric infection in patients with OAL. A systematic review of studies assessing H. pylori in patients with OAL was conducted by searching electronic databases from their inception to May 2019. Pooled positivity for H. pylori in OAL specimens detected by polymerase chain reaction, and pooled prevalence of H. pylori gastric infection, were calculated with 95% confidence interval (CI). Eleven studies with 308 patients were included. Pooled positivity for H. pylori was 16.8% in all OALs and 22.7% in MALT OAL, with high heterogeneity among studies. Pooled prevalence of H. pylori gastric infection in patients with OAL was 34.7%, with low statistical heterogeneity. In conclusion, H. pylori seems to be involved in a subset of OAL, but the heterogeneity found needs to be investigated in further studies. The prevalence of H. pylori gastric infection in patients with OAL does not seem to differ from that of the general population.

Prevalence of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis Determined by Molecular Testing in Ocular Adnexa Lymphoma Specimens

OBJECTIVES

To assess the prevalence of Chlamydia psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis in ocular adnexa lymphoma (OAL) determined by molecular testing in different countries and the potential association of Chlamydia infection with mucosa-associated lymphoid tissue (MALT) histotype by performing a systematic review and meta-analysis.

METHODS

Electronic databases were searched for studies assessing the presence of Chlamydia in OAL. Pooled prevalence of the three Chlamydia species was calculated in each country. An odds ratio was calculated for the association between Chlamydia and MALT histotype, with a significant P < .05.

RESULTS

Thirty-seven studies with 1,188 OALs were included. Pooled prevalence of C psittaci, C pneumoniae, and C trachomatis by country was done. Chlamydia infection was significantly associated with MALT histotype (odds ratio, 2.183; P = .027).

CONCLUSIONS

The involvement of C psittaci in OAL is highly variable, with the highest prevalence in Italy and Korea. Chlamydia is associated with MALT histotype.

Hepatitis C virus in MALT-lymphoma of the ocular adnexa

OBJECTIVE

Hepatitis C virus (HCV) has been proposed as a possible etiologic factor in ocular adnexal marginal zone lymphoma (OAML). We aimed to assess the prevalence of HCV infection in patients with OAML through a systematic review and meta-analysis.

METHODS

Electronic databases were searched from their inception to August 2019 for studies assessing HCV seroprevalence in patients with OAML. Pooled prevalence of HCV infection was calculated with 95 % confidence interval (CI). Statistical heterogeneity among studies was quantified via the inconsistency index (I²). Funnel plot symmetry was used to assess the risk of bias across studies.

RESULTS

Nine studies with 360 patients were included. Overall pooled prevalence of HCV in OAML was 12.7 %, with low statistical heterogeneity (I² = 17.4 %) and with asymmetrical funnel plot. The studies clustered into two groups: 5 studies (3 from Italy and 2 multicenter with a major Italian contribution) showed a higher HCV prevalence in OAML (15.6 %), while the other 4 (from countries other than Italy) showed a lower prevalence (4.7 %); in both subgroups, statistical heterogeneity was null (I² = 0%) and funnel plot was symmetrical.

CONCLUSION

HCV might be a significant etiologic factor of OAML in Italy.

The role of infectious agents in cancer of the ocular region

The purpose of the study was to investigate the association between infectious agents and the development of cancer in the ocular adnexa. A comprehensive literary study was carried out, reviewing and summarizing previous reports on the topic. A broad range of malignancies of the ocular adnexa are associated with infectious agents. A strong association and possible causal relationship between the infectious agent and the development of ocular adnexal cancer are seen in Merkel cell carcinoma (Merkel cell polyomavirus), Burkitt lymphoma (Epstein-Barr virus) and Kaposi sarcoma (human herpesvirus 8). Infection with Chlamydia psittaci has been associated with the development of extranodal marginal zone B-cell lymphoma in Italy. Human papillomavirus infection has been associated with the development of squamous cell carcinomas of the ocular adnexa, although with a highly variable reported prevalence. By exploring the role of infectious agents in the ocular adnexa and the mechanism by which they contribute to oncogenesis, the diagnostics, management and prevention of these malignancies may also improve. Antibiotic treatment and vaccines against infectious agents may be valuable in future treatment. Additionally, the presence of infectious agents within the tumours may have a prognostic or predictive value.