Primary lymphoma of the ocular adnexa (orbital lymphoma) and primary intraocular lymphoma

Lymphoma involvement of the eyelid and eye

Lymphomas of the eye and ocular adnexa are rare lymphoproliferative diseases of the ocular and ocular adnexal tissue. The incidence of these diseases has been rapidly increasing over the past few decades. The exact pathogenesis remains unknown, but it is postulated to be multifactorial and includes genetic aberrations, epigenetic and environmental factors, infectious agents, and chronic antigenic stimulation. The majority of ocular and ocular adnexal lymphomas are of B-cell origin, except for eyelid lymphomas, which are more often of T-cell type. Lymphoproliferative diseases of ocular and ocular adnexal structures are either primary, when they arise in the eye, orbit, lacrimal gland, eyelid, and/or conjunctiva, or secondary extranodal manifestation of systemic lymphoma. Diagnosis is challenging and requires a multidisciplinary approach involving ophthalmologists, dermatologists, oncologists, and radiation oncologists.

Incidental Diagnosis of Four Lid Orbital Lymphoma during a Blepharoplasty

Chronic lymphocytic leukemia is characterized by the accumulation of mature CD5-positive B-cells in the lymphoid organs.1 Extranodal involvement occurs in up to 10% of cases and can arise in various tissues, including the orbit. Less than 400 cases of orbital lymphoma are diagnosed per year in the United States, typically manifesting as a form of B-cell non-Hodgkin lymphoma, with extranodal marginal zone B-cell lymphoma being the most common subtype. Orbital lymphoma typically presents with proptosis and a palpable mass; however, patients may also have a relatively benign examination. Here, we present a 76-year-old man with symmetric dermatochalasis and marked fat prolapse of all four lids, who was incidentally diagnosed with secondary orbital lymphoma in all four eyelids during a cosmetic four lid blepharoplasty. His history was significant for RAI Stage 0 chronic lymphocytic leukemia diagnosed 15 years before consultation. Orbital lymphoma presenting as orbital fat prolapse has only been reported a few times in the literature. To our knowledge, this is the first case of secondary orbital lymphoma in all four eyelids found incidentally during an aesthetic four lid blepharoplasty.

Vogt-Koyanagi-Harada disease developed during chemotherapy for Hodgkin lymphoma: a case report

BACKGROUND

Ocular manifestations are known for non-Hodgkin lymphoma, but are rare for Hodgkin lymphoma. We report a case of Vogt-Koyanagi-Harada (VKH) disease presenting as serous retinal detachment and uveitis in both eyes in a child undergoing chemotherapy for Hodgkin lymphoma.

CASE PRESENTATION

The patient was a 7-year-old boy with stage IIB Hodgkin lymphoma (nodular lymphocyte predominant type) who was undergoing chemotherapy, including 2 cycles of the OEPA regimen and 1 cycle of the COPDAC regimen. Two days after the end of the COPDAC regimen, the patient complained of headache and of blurred and decreased vision in both eyes. On the basis of optic symptoms, such as uveitis and serous retinal detachment in both eyes, increased cell counts in cerebrospinal fluid, and positivity for human leukocyte antigen (HLA)-DR4 in peripheral blood cells, incomplete VKH disease was diagnosed. Intravenous treatment with high-dose prednisolone (60mg/m2/day) for 7 days improved both visual acuity and serous retinal detachment and enabled the remains of the COPDAC chemotherapy cycle to be administered. With prednisolone treatment, visual acuity improved from 20/500 to 20/20 in the right eye and from 20/63 to 20/25 in the left eye. Because multiple vitiligo lesions later appeared in the abdomen, complete VKH disease was finally diagnosed.

CONCLUSION

The onset of VKH disease occurred during chemotherapy for Hodgkin lymphoma. The patient was HLA-DR4-positive and might have had a predisposition to develop autoimmune diseases, including VKH disease. However, the anticancer drugs administered to this patient have not been reported to cause uveitis. Whether Hodgkin lymphoma triggered the development of VKH remains unclear. Early diagnosis of VKH disease and prompt treatment with high-dose prednisone enabled the patient to maintain good visual function despite chemotherapy for Hodgkin lymphoma.

End-to-End Deep-Learning-Based Diagnosis of Benign and Malignant Orbital Tumors on Computed Tomography Images

Determining the nature of orbital tumors is challenging for current imaging interpretation methods, which hinders timely treatment. This study aimed to propose an end-to-end deep learning system to automatically diagnose orbital tumors. A multi-center dataset of 602 non-contrast-enhanced computed tomography (CT) images were prepared. After image annotation and preprocessing, the CT images were used to train and test the deep learning (DL) model for the following two stages: orbital tumor segmentation and classification. The performance on the testing set was compared with the assessment of three ophthalmologists. For tumor segmentation, the model achieved a satisfactory performance, with an average dice similarity coefficient of 0.89. The classification model had an accuracy of 86.96%, a sensitivity of 80.00%, and a specificity of 94.12%. The area under the receiver operating characteristics curve (AUC) of the 10-fold cross-validation ranged from 0.8439 to 0.9546. There was no significant difference on diagnostic performance of the DL-based system and three ophthalmologists (p > 0.05). The proposed end-to-end deep learning system could deliver accurate segmentation and diagnosis of orbital tumors based on noninvasive CT images. Its effectiveness and independence from human interaction allow the potential for tumor screening in the orbit and other parts of the body.

Long-Term Clinical Outcomes and Sequelae of Therapy in Early-Stage Orbital Mucosa-Associated Lymphoid Tissue Lymphoma

INTRODUCTION

Orbital mucosa-associated lymphoid tissue (MALT) lymphoma, which are rare and indolent, often present at an early stage. We report the efficacy and safety outcomes of treatment in these patients.

METHODS

We analyzed adult patients with stage IE or IIE orbital MALT lymphoma between 1999 and 2017 treated at our institute. We assessed local control (LC) rates, overall survival (OS), relapse-free survival (RFS) using Kaplan Meier method and the incidence of late toxicities.

RESULTS

Seventy patients were analyzed for clinical outcomes. The median age at diagnosis was 52 years (IQR-45-62 years). Radiotherapy was offered to 97% of patients and the dose ranged from 36 to 45 Gy. Chemotherapy was administered in 5(7.1%) patients. Relapse occurred in 8 patients (local: 2, distant: 6). At a median follow-up of 101 months (IQR-47-146 months), the median OS and RFS was not reached. 8-year OS, RFS and LC rates were 96.5%, 88.5%, 96.7% respectively. Univariate analysis showed age ≤60 years and lacrimal involvement significantly correlated with better OS (P = .01 and .04, respectively). Cataract was the most common sequelae observed in 31 patients (44.3%).

CONCLUSION

Moderate doses of radiotherapy are curative in early-stage orbital MALT lymphoma with favorable clinical outcomes. Lower doses of radiation can reduce the toxicity further, without compromising efficacy.

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.

Bag-of-features-based radiomics for differentiation of ocular adnexal lymphoma and idiopathic orbital inflammation from contrast-enhanced MRI

OBJECTIVES

To evaluate the effectiveness of bag-of-features (BOF)-based radiomics for differentiating ocular adnexal lymphoma (OAL) and idiopathic orbital inflammation (IOI) from contrast-enhanced MRI (CE-MRI).

METHODS

Fifty-six patients with pathologically confirmed IOI (28 patients) and OAL (28 patients) were randomly divided into training (n = 42) and testing (n = 14) groups. One hundred sixty texture features extracted from the CE-MR image were encoded into the BOF representation with fewer features. The support vector machine (SVM) with a linear kernel was used as the classifier. Data augmented was performed by cropping orbital lesions in different directions to alleviate the over-fitting problem. Student's t test and the Holm-Bonferroni method were employed to compare the performance of different analysis methods. The chi-square test was used to compare the analysis with MRI and human radiological diagnosis.

RESULTS

In the independent testing group, the differentiation by the BOF features with augmentation achieved an area under the curve (AUC) of 0.803 (95% CI: 0.725-0.880), which was significantly higher than that of the BOF features without augmentation and that of the texture features (p < 0.05). In addition, the same radiomic analysis with pre-contrast MRI obtained an AUC of 0.618 (95% CI: 0.560-0.677), which was significantly lower than that with CE-MRI. The diagnostic performance of the analysis with CE-MRI was significantly better than the radiology resident (p < 0.05) but had no significant difference with the experienced radiologist, even though there was less consistency between the radiomic analysis and the human visual diagnosis.

CONCLUSIONS

The BOF-based radiomics may be helpful for the differentiation between OAL and IOI.

KEY POINTS

• It is challenging to differentiate OAL from IOI due to the similar clinical and image features. • Radiomics has great potential for the noninvasive diagnosis of orbital diseases. • The BOF representation from patch to image may help the differentiation of OAL and IOI.

Classification, diagnosis, and management of conjunctival lymphoma

Lymphoma is a malignant lymphoproliferative tumor that can involve the conjunctiva. Approximately 5-15% of all extranodal lymphomas are found in the ocular adnexal region, with approximately 25% of those involving the conjunctiva. Ninety-eight percent of conjunctival lymphomas arise from B-lymphocytes. The most common subtype of conjunctival lymphoma is extranodal marginal zone lymphoma (80%), followed by follicular lymphoma (8%), diffuse large B-cell lymphoma (3%) and mantle cell lymphoma (3%). Natural killer and T cells (NK/T) are rare causes of lymphoma. While most conjunctival lymphomas are localized to the ocular adnexa at the time of presentation, systemic examination and management are of key importance in the long-term care of the patient. This review outlines the classification, etiology, presentation, diagnosis, and management of conjunctival lymphoma. The novel use of high resolution optical coherence tomography, both as a diagnostic tool and as a means for ongoing evaluation during treatment, is illustrated. Treatment options discussed include external beam radiation, chemotherapy, immunotherapy, antibiotic therapy, and combination regimens. Future investigation of the etiology and pathogenesis of conjunctival lymphoma is expected to reveal opportunities for innovative and individualized therapeutic agents. Collaboration between multiple disciplines is key in the advancement of the field.

MR-based radiomics signature in differentiating ocular adnexal lymphoma from idiopathic orbital inflammation

OBJECTIVES

To assess the value of the MR-based radiomics signature in differentiating ocular adnexal lymphoma (OAL) and idiopathic orbital inflammation (IOI).

METHODS

One hundred fifty-seven patients with pathology-proven OAL (84 patients) and IOI (73 patients) were divided into primary and validation cohorts. Eight hundred six radiomics features were extracted from morphological MR images. The least absolute shrinkage and selection operator (LASSO) procedure and linear combination were used to select features and build radiomics signature for discriminating OAL from IOI. Discriminating performance was assessed by the area under the receiver-operating characteristic curve (AUC). The predictive results were compared with the assessment of radiologists by chi-square test.

RESULTS

Five radiomics features were included in the radiomics signature, which differentiated OAL from IOI with an AUC of 0.74 and 0.73 in the primary and validation cohorts respectively. There was a significant difference between the classification results of the radiomics signature and those of a radiology resident (p < 0.05), although there was no significant difference between the results of the radiomics signature and those of a more experienced radiologist (p > 0.05).

CONCLUSIONS

Radiomics features have the potential to differentiate OAL from IOI.

KEY POINTS

• Clinical and imaging findings of OAL and IOI often overlap, which makes diagnosis difficult. • Radiomics features can potentially differentiate OAL from IOI non invasively. • The radiomics signature discriminates OAL from IOI at the same level as an experienced radiologist.

Mucosa-associated lymphoid tissue lymphoma with intraocular and orbital involvement: case presentation and review of the literature

Primary ocular lymphomas are typically confined to either the eye or the orbit. Rarely, in immune-competent patients, lymphomas affect both the eye and the orbit simultaneously. Mucosa-associated lymphoid tissue (MALT) lymphomas are the most common ocular lymphomas. They usually present primarily in the orbit but sometimes can present primarily in intraocular tissue. MALT lymphomas that occur initially in the uvea can sometimes spread to the adjacent orbit. We report a case of progressively enlarging MALT lymphoma in a 62-year-old immune-competent patient causing a severe mass effect in the orbit and simultaneously presenting with intraocular involvement. There was radiographic evidence of lymphoma confined to the orbit with intraocular involvement. The simultaneous presentation makes it difficult to determine if the lymphoma initially presented in the orbit or intraocular tissue, although the orbital component was more impressive. The case also includes a literature review of simultaneous orbital and intraocular MALT lymphomas. The patient responded to systemic chemotherapy with regression in size of the lymphoma, relief of the mass effect seen in the orbit, and the regression of the intraocular involvement.

Lymphoma and inflammation in the orbit: Diagnostic performance with diffusion-weighted imaging and dynamic contrast-enhanced MRI

PURPOSE

To investigate the diagnostic performance of diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), and the combination of both in the differential diagnosis of lymphoma and inflammation in the orbit.

MATERIALS AND METHODS

This retrospective study was approved by the Institutional Review Board and the informed consent requirement was waived. A total of 53 patients underwent preoperative 3T MRI. Parameters of DWI and DCE MRI were evaluated in these 30 patients with orbital lymphoma and 23 patients with orbital inflammation. The diagnostic performance was evaluated using receiver operating characteristic curve analysis.

RESULTS

Apparent diffusion coefficient (ADC) values and parameters derived from DCE MRI of orbital lymphoma and orbital inflammation differed significantly (ADC, T_max , contrast index [CI], enhancement ratio [ER], and washout ratio [WR]: P < 0.001, P = 0.008, P < 0.001, P < 0.001, and P = 0.005 for reviewer 1, respectively; P < 0.001, P = 0.004, P < 0.001, P < 0.001, and P < 0.001 for reviewer 2, respectively). Sensitivity, specificity, and accuracy values of DWI were 76.67%, 100%, and 86.79% for reviewer 1; 70%, 95.65%, and 81.13% for reviewer 2, respectively. The combination of both were 90%, 86.96%, and 88.68% for reviewer 1; 93.33%, 78.26%, and 86.79% for reviewer 2, respectively. The combination of both was significantly superior to DWI for differentiation of orbital lymphoma from orbital inflammation (P = 0.016 for reviewer 1; P = 0.001 for reviewer 2).

CONCLUSION

The combination of DWI and DCE MRI can improve diagnostic performance in differentiating lymphoma from inflammation in the orbit compared with DWI alone.

LEVEL OF EVIDENCE

3 J. MAGN. RESON. IMAGING 2017;45:1438-1445.

Radiotherapy of indolent orbital lymphomas : Two radiation concepts

PURPOSE

The aim of this work was to retrospectively analyze efficacy, toxicity, and relapse rates of conventional (CRT) and low-dose radiotherapy (LDRT) in patients with indolent orbital lymphomas.

PATIENTS AND METHODS

From 1987-2014, 45 patients (median age 64 years) with 52 lesions of indolent orbital lymphomas were treated with CRT (median dose 36 Gy, range 26-46 Gy) and 7 patients (median age 75 years) with 8 lesions were treated with LDRT (2 fractions of  2.0 Gy).

RESULTS

Median follow-up was 133 months (range 2-329 months) in the CRT group and 25 months (range 10-41 months) in the LDRT group. Overall response rates were 97.7 % (CRT) and 100 % (LDRT). The 2‑ and 5‑year local progression-free survival (PFS) rates were 93.5 and 88.6 %, distant PFS 95.0 and 89.9 %, and overall survival 100 and 85.6 % after CRT. In the LDRT group, 2‑year local PFS and overall survival remained 100 %, respectively, and distant PFS 68.6 %. Acute radiotherapy-related complications (grades 1-2) were detected in virtually all eyes treated with CRT. Cataracts developed in only patients who were irradiated with more than 34 Gy. LDRT was well tolerated with only mild acute and late complications.

CONCLUSION

Primary radiotherapy of indolent orbital lymphomas is an effective treatment with high response rates and excellent local control in CRT and LDRT. In combination with close follow-up, LDRT may be an attractive alternative since re-irradiation even with conventional doses is still feasible.

Ocular Adnexal Lymphoma Presenting with Visual Loss

Context:

Elderly patients with visual loss often have age-related macular degeneration, diabetic retinopathy, glaucoma, and cataract as common causes of visual loss. Other less common etiologies should be considered, especially in those presenting with systemic associations.

Case Report:

The patient discussed in our review is an 80-year-old female, with a history of diabetic retinopathy and macular degeneration who presented with a sudden deterioration of vision. While this was initially attributed to diabetic retinopathy, she was eventually noted to have a salmon patch lesion in her conjunctiva, diagnosed on biopsy to be a diffuse large B-cell lymphoma.

Conclusion:

Because of the significant rate of disseminated disease among patients with lymphomas in the orbit that carries a worse prognosis, early diagnosis is essential to promote better overall survival of these patients. We describe here a patient diagnosed with conjunctival lymphoma associated with pronounced visual loss and review the literature on this subject.

Orbital apex disorders: a case series

Orbital apex syndrome is an uncommon disorder characterized by ophthalmoplegia, proptosis, ptosis, hypoesthesia of the forehead, and vision loss. It may be classified as part of a group of orbital apex disorders that includes superior orbital fissure syndrome and cavernous sinus syndrome. Superior orbital fissure syndrome presents similarly to orbital apex syndrome without optic nerve impairment. Cavernous sinus syndrome includes hypoesthesia of the cheek and lower eyelid in addition to the signs seen in orbital apex syndrome. While historically described separately, these three disorders share similar causes, diagnostic course, and management strategies. The purpose of this study was to report three cases of orbital apex disorders treated recently and to review the literature related to these conditions. Inflammatory and vascular disorders, neoplasm, infection, and trauma are potential causes of orbital apex disorders. Management is directed at the causative process. The cases described represent a rare but important group of conditions seen by the maxillofacial surgeon. A review of the clinical presentation, etiology, and management of these conditions may prompt timely recognition and treatment.

[Malignant tumours of the eye: Epidemiology, diagnostic methods and radiotherapy]

Malignant tumours of the eye are not common, barely representing 1 % of all cancers. This article aims to summarise, for each of the main eye malignant diseases, aspects of epidemiology, diagnostic methods and treatments, with a focus on radiation therapy techniques. The studied tumours are: eye metastasis, intraocular and ocular adnexal lymphomas, uveal melanomas, malignant tumours of the conjunctive, of the lids, and retinoblastomas. The last chapter outlines ocular complications of radiation therapy and their management.

Rituximab as Single Agent in Primary MALT Lymphoma of the Ocular Adnexa

Ocular Adnexal Lymphomas are the first cause of primary ocular malignancies, and among them the most common are MALT Ocular Adnexal Lymphomas. Recently systemic immunotherapy with anti-CD20 monoclonal antibody has been investigated as first-line treatment; however, the optimal management for MALT Ocular Adnexal Lymphomas is still unknown. The present study evaluated retrospectively the outcome of seven consecutive patients with primary MALT Ocular Adnexal Lymphomas, of whom six were treated with single agent Rituximab. All patients received 6 cycles of Rituximab 375 mg/mq every 3 weeks intravenously. The overall response rate was 100%; four patients (67%) achieved a Complete Remission, and two (33%) achieved a partial response. In four patients an additional Rituximab maintenance every 2-3 months was given for two years. After a median follow-up of 29 months (range 8-34), no recurrences were observed, without of therapy- or disease-related severe adverse events. None of the patients needed additional radiotherapy or other treatments. Rituximab as a single agent is highly effective and tolerable in first-line treatment of primary MALT Ocular adnexal Lymphomas. Furthermore, durable responses are achievable with the same-agent maintenance. Rituximab can be considered the agent of choice in the management of an indolent disease in whom the "quality of life" matter is of primary importance.

Outcomes of primary lymphoma of the ocular adnexa (orbital lymphoma) treated with radiotherapy

AIMS

Low-grade ocular adnexal lymphoma is a rare disease and often treated with local radiotherapy to varying doses. Most previously reported studies have a very heterogeneous patient population and treatments. We report the outcomes from a 10 year cohort of patients at our institution treated with primary radiation therapy.

MATERIALS AND METHODS

We analysed a retrospective case series of patients with stage IE low-grade ocular adnexal lymphoma including a review of case notes, histological reports and radiotherapy charts. We assessed local and distant tumour control and relapse rates in addition to toxicity. Disease-free survival was estimated using the Kaplan-Meier method.

RESULTS

In total, 81 patients and 85 orbits were treated with primary radiotherapy to a median dose of 30 Gy in 15 fractions over 3 weeks. Seventy-nine per cent were treated with standard MV external beam radiotherapy to the whole orbit and 21% with a lens-sparing technique. The median follow-up was 4.4 years (range 0.2-10.4). Local control rates were 100%, with 5% of patients experiencing disease relapse elsewhere. No patients died from lymphoma. Cumulative acute toxicity rates were 51% (mainly erythema and conjunctivitis) and late toxicity rates were 8% (mainly cataract). The lens-sparing technique was associated with a significant reduction in cataract rate (P = 0.013) and an increase in acute toxicity (P < 0.001).

CONCLUSIONS

This study has shown excellent local control rates and acceptable toxicity from the treatment of stage IE low-grade ocular adnexal lymphoma with localised radiotherapy to a median dose of 30 Gy in 15 fractions over 3 weeks.

Marginal zone mucosa associated lymphoid tissue diffuse large B cell lymphoma

Context:

Non-Hodgkin's lymphomas (NHL) primarily involving the orbit, is relatively uncommon. Rarely two pathologically different NHL cell types have been found to be coexistent.

Case Report:

We report a case of orbital lymphoma in a 62-year-old male with rare histopathological findings secondary to transformation of once cell type into another. Tissue diagnosis and molecular studies led to revelation of diffuse large B cell lymphoma evolving from MALT lymphoma.

Conclusion:

Proliferation of two morphologically and phenotypically different B cells resulting in malignancy has not been found in the orbit so far. They are usually aggressive tumors and require chemo-immunotherapy.

Asynchronous presentation of follicle center lymphoma and reactive lymphoid hyperplasia of the ocular adnexa

Although ocular lymphoproliferative diseases may be rarely encountered by dermatopathologists, the frequency may increase particularly as more and more subspecialties rely on dermatopathology services. Emerging data suggest that there are some similarities between ocular and cutaneous lymphoproliferative diseases with respect to their clinical behavior, prognosis, and cytogenetics. In this case report, a patient with ocular follicle center lymphoma who subsequently developed ocular reactive lymphoid hyperplasia is presented with an accompanying review of the literature on the subjects. The encounter of both follicular center lymphoma and reactive lymphoid hyperplasia in the same patient provides a rare opportunity to compare and contrast the clinical, histological, and immunohistochemical findings of the respective lymphoproliferative diseases situated at opposite ends of the spectrum.

Primary intraocular lymphoma

Primary intraocular lymphoma (PIOL) is an ocular malignancy that is a subset of primary central system lymphoma (PCNSL). Approximately one-third of PIOL patients will have concurrent PCNSL at presentation, and 42-92% will develop PCNSL within a mean of 8-29 months. Although rare, the incidence has been rising in both immunocompromised and immunocompetent populations. The majority of PIOL is diffuse large B-cell lymphoma, though rare T-cell variants are described. Recently, PIOL has been classified by main site of involvement in the eye, with vitreoretinal lymphoma as the most common type of ocular lymphoma related to PCNSL. Diagnosis remains challenging for ophthalmologists and pathologists. PIOL can masquerade as noninfectious or infectious uveitis, white dot syndromes, or occasionally as other neoplasms such as metastatic cancers. Laboratory diagnosis by cytology has been much aided by the use of immunocytochemistry, flow cytometry, biochemical finding of interleukin changes (IL10:IL6 ratio > 1), and cellular microdissection with polymerase chain reaction amplification for clonality. Use of several tests improves the diagnostic yield. Approaches to treatment have centered on systemic methotrexate-based chemotherapy, often with cytarabine (Ara-C) and radiotherapy. Use of intravitreal chemotherapy with methotrexate (0.4 mg/0.1 mL) is promising in controlling ocular disease, and intravitreal rituximab (anti-CD20 monoclonal antibody) has also been tried. Despite these advances, prognosis remains poor.