Unilateral acute iris transillumination syndrome with glaucoma and iris pigment epithelium dispersion simulating iris melanoma

Purpose

To report a patient with a unilateral presentation of glaucoma, pain, and acute iris transillumination syndrome simulating iris melanoma.

Observations

A 53-year-old male presented with blurred vision and pain in his right eye several weeks following a respiratory sinus infection managed by oral azithromycin. Examination of the right eye was notable for elevated intraocular pressure of 46 mm Hg, an irregular mid-dilated pupil, and diffuse iris transillumination with pigmentary seeding on the iris surface, in the anterior chamber angle, and on the sclera, suspicious for diffuse iris melanoma with glaucoma and extrascleral extension. Ultrasound biomicroscopy (UBM) of the right eye revealed circumferential anterior chamber angle and trabecular meshwork involvement by an infiltrative process corresponding to the pigmented cells noted clinically, while the ciliary body was unremarkable. Following enucleation, histopathology showed extensive necrosis of the iris pigment epithelium, sphincter, and dilator muscles with melanophagic infiltration in the anterior chamber angle and episclera, mild chronic non-granulomatous iridocyclitis, and no evidence of a melanocytic neoplasm. Although immunohistochemical studies for herpes simplex virus (HSV) types 1 and 2, varicella-zoster virus, and cytomegalovirus were negative, qualitative real-time polymerase chain reaction on paraffin-embedded tissue detected HSV-1 DNA. The combined clinical, pathologic, and molecular findings were compatible with unilateral acute iris transillumination syndrome, likely HSV-1 associated.

Conclusion and Importance

Unilateral acute iris transillumination syndrome with diffuse iris pigment epithelial loss can simulate iris melanoma. Prompt herpes viral studies may be informative.

Nitric oxide suppression by secreted frizzled-related protein 2 drives retinoblastoma

Retinoblastoma is a cancer of the infant retina primarily driven by loss of the Rb tumor suppressor gene, which is undruggable. Here, we report an autocrine signaling, mediated by secreted frizzled-related protein 2 (SFRP2), which suppresses nitric oxide and enables retinoblastoma growth. We show that coxsackievirus and adenovirus receptor (CXADR) is the cell-surface receptor for SFRP2 in retinoblastoma cells; that CXADR functions as a "dependence receptor," transmitting a growth-inhibitory signal in the absence of SFRP2; and that the balance between SFRP2 and CXADR determines nitric oxide production. Accordingly, high SFRP2 RNA expression correlates with high-risk histopathologic features in retinoblastoma. Targeting SFRP2 signaling by SFRP2-binding peptides or by a pharmacological inhibitor rapidly induces nitric oxide and profoundly inhibits retinoblastoma growth in orthotopic xenograft models. These results reveal a cytokine signaling pathway that regulates nitric oxide production and retinoblastoma cell proliferation and is amenable to therapeutic intervention.

Giant cell arteritis versus Takayasu's Arteritis: Two sides of the same coin?

There are multiple vasculitides which are distinguished based on multiple criteria, including size of affected vessels, distribution of vessels affected, histopathologic differences, genetic factors, and age at presentation. Takayasu's arteritis (TkA) and giant cell arteritis (GCA) are the two main medium to large vessel vasculitides. These vasculitides are associated with different racial predilections, vascular distributions, age groups, diagnostic criteria, and treatments. Nevertheless, the many shared histopathologic features, genetic factors, and overlap in presentation of these two diseases suggest that they may actually be variable presentations of the same disease process, i.e., large vessel vasculitis. This article will review the genetics, histopathology, disease mechanisms, and diagnostic criteria for both TkA and GCA. Overall, despite major advances our understanding of these two diseases, it is still debated whether these two large vessel vasculitides represent two distinct diseases processes or simply variations of the same disease.

Microsporidial Stromal Keratitis: Epidemiological Features, Slit-Lamp Biomicroscopic Characteristics, and Therapy

PURPOSE

Microsporidial stromal keratitis is a rare form of infectious keratitis, with only 7 cases reported in the United States to date. This study was performed to evaluate risk factors, clinical features, and response to therapy.

METHODS

A retrospective review of the medical records of all patients diagnosed with microsporidial stromal keratitis seen in the practices of the authors between 1999 and 2020 was performed. Diagnosis was determined by cytology or histopathology in corneal specimens. Risk factors, presence or absence of distinctive clinical features, and response to medical and surgical therapies were recorded.

RESULTS

Nine patients-7M:2F, aged 7 to 99 years-with microsporidial stromal keratitis were identified. Exposures to recreational water and hymenopteran insect bites, both epidemiologically linked risk factors for systemic microsporidial infection, were identified in our patients. Presence of stromal edema with features of disciform keratitis and a distinctive granular keratitis were observed in 6 of 9 and 5 of 9 patients, respectively. Poor response to medical therapy was noted. Penetrating keratoplasty was effective in curing the infection. Final visual acuity was 20/40 or better in 6 of 9 patients.

CONCLUSIONS

In patients with slowly progressive keratitis, history of exposure to recreational water or hymenopteran insects should be sought. In patients with corneal edema consistent with disciform keratitis, with evolution to a granular keratitis, microsporidia should be considered in the differential diagnosis. In cases of established microsporidial stromal keratitis, penetrating keratoplasty should be considered if prompt response to medical therapy is not noted.

Abstract 638: Enhancing the molecular diagnosis, prognosis, and treatment monitoring of retinoblastoma using cell free DNA in aqueous humor

Purpose: All previous studies of retinoblastoma (RB) aqueous humor (AH) analysis for tumor-derived cell-free DNA (cfDNA) have focused on sampling AH from eyes undergoing therapy; results from AH liquid biopsy at the time of diagnosis have not yet been published. Herein, we detail the diagnostic and prognostic genomic biomarkers found in the AH cfDNA from 7 RB eyes at diagnosis, each with longitudinal evaluation of over 12 months in follow-up.

Methods: Subjects included 7 eyes of 6 RB patients who underwent AH sampling at diagnosis. CfDNA from each AH sample was isolated and sequenced to assess genome-wide somatic copy number alterations (SCNAs), followed by targeted resequencing and mutation detection using a custom hybridization panel for RB1 and MYCN. Results were compared to peripheral blood RB1 testing and matched tumor samples, when available. Tumor fraction (TFx) was calculated using ichorCNA.

Results: Five of 7 diagnostic AH samples contained highly recurrent RB SCNAs, 4 with large scale alterations and 1 with a focal RB1 gene deletion. Mutational analysis of AH cfDNA identified pathogenic somatic variants in 5 diagnostic AH samples with high variant allele frequency, while the remaining 2 diagnostic AH samples had either a high TFx from SCNAs or a focal MYCN amplification. Taken together, somatic tumoral genomic information was detected in all 7 diagnostic AH samples. The 2 eyes that required enucleation had poor prognostic biomarkers (chromosome 6p gain and MYCN amplification) present at the time of diagnosis. TFx from longitudinal AH sampling corresponded to treatment response over time in all cases for which sequential AH samples were available.

Conclusions: This study demonstrates that AH sampling at diagnosis is both feasible and safe. Molecular profiling of AH provides a plethora of diagnostic and prognostic information from only a single 0.1 mL AH sample.

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Citation Format: Liya Xu, Mary E. Kim, Ashley Polski, Rishvanth K. Prabakar, Chen-Ching Peng, Patricia Chévez-Barrios, Jonathan W. Kim, Rachana Shah, Rima Jubran, Peter Kuhn, David Cobrinik, James Hicks, Jesse L. Berry. Enhancing the molecular diagnosis, prognosis, and treatment monitoring of retinoblastoma using cell free DNA in aqueous humor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 638.

Eye cancer in a young male with a vaping history

We report a new observation of conjunctival intraepithelial neoplasia (CIN) in a young man following years of electronic cigarette use. A 22-year-old man with a 5-year electronic cigarette use (vaping) developed painless unilateral blurred vision in the right eye from mild superficial corneal opacification, unresponsive to topical antiviral therapy. Corneal scraping documented no infectious etiology. The abnormality persisted for 1 year and superficial keratectomy revealed high-grade CIN with enlarged pleomorphic and dyskeratotic cells. Interferon-alpha-2b was instituted. In this case, chronic exposure to electronic cigarette vapors (vaping) could have been associated with CIN in this young patient.

Bilateral orbital inflammation in a 6-month old with SARS-CoV-2 infection

A 6-month-old female presented with bilateral periorbital edema for 7 days. Laboratory testing was significant for active SARS-CoV-2 infection. Neuroimaging demonstrated soft tissue changes within the bilateral orbits and enlargement of the bilateral lacrimal glands. Although the patient initially improved with corticosteroid treatment, she later returned with recurrent left periorbital and eyelid edema. Orbital biopsy was performed and demonstrated findings in the lacrimal gland and the adjacent fibroconnective tissues that are similar to those of prior lung specimens seen in SARS-CoV-2 patients. Final diagnosis was bilateral orbital inflammation with features presumed secondary to SARS-CoV-2 infection. To the best of our knowledge, this is one of the first reports to document bilateral orbital inflammation as a sign of SARS-CoV-2 infection in the pediatric population with the associated pathological findings.

Establishing the Clinical Utility of ctDNA Analysis for Diagnosis, Prognosis, and Treatment Monitoring of Retinoblastoma: The Aqueous Humor Liquid Biopsy

Simple Summary

Due to prohibition of direct tumor biopsy for patients with retinoblastoma, the prospect of a liquid biopsy for the identification of tumor derived biomarkers for this cancer is enticing. The aqueous humor (AH) is a rich source of eye-specific tumoral genomic information. This is the first prospective study wherein we demonstrate that molecular profiling of the AH at diagnosis and longitudinally throughout therapy has clinical utility for diagnosis, prognosis, and monitoring of treatment response. Tumoral genomic information was detected in 100% of diagnostic aqueous humor samples, including single nucleotide variants in the RB1 tumor suppressor gene and large-scale somatic chromosomal alterations. All eyes that failed therapy and required enucleation had poor prognostic biomarkers for ocular salvage present in the aqueous humor at time of diagnosis. This highlights the potential of the AH liquid biopsy for direct clinical applications to precision oncology to direct genome-specific, personalized treatment for retinoblastoma patients.

Abstract

Because direct tumor biopsy is prohibited for retinoblastoma (RB), eye-specific molecular biomarkers are not used in clinical practice for RB. Recently, we demonstrated that the aqueous humor (AH) is a rich liquid biopsy source of cell-free tumor DNA. Herein, we detail clinically-relevant molecular biomarkers from the first year of prospective validation data. Seven eyes from 6 RB patients who had AH sampled at diagnosis and throughout therapy with ≥12 months of follow-up were included. Cell-free DNA (cfDNA) from each sample was isolated and sequenced to assess genome-wide somatic copy number alterations (SCNAs), followed by targeted resequencing for pathogenic variants using a RB1 and MYCN custom hybridization panel. Tumoral genomic information was detected in 100% of diagnostic AH samples. Of the seven diagnostic AH samples, 5/7 were positive for RB SCNAs. Mutational analysis identified RB1 variants in 5/7 AH samples, including the 2 samples in which no SCNAs were detected. Two eyes failed therapy and required enucleation; both had poor prognostic biomarkers (chromosome 6p gain or MYCN amplification) present in the AH at the time of diagnosis. In the context of previously established pre-analytical, analytical, and clinical validity, this provides evidence for larger, prospective studies to further establish the clinical utility of the AH liquid biopsy and its applications to precision oncology for RB.

Locally Invasive Diffuse Iris Ring Melanoma Presenting as Unilateral Severe Glaucoma: Case Report and Review of Molecular Genetics

We report the clinical history and histopathological findings in a case of diffuse iris ring melanoma (DIM) and review the most recent literature and modern molecular genetics of this entity. An 85-year-old Hispanic man presented with severe unilateral glaucoma, managed at an outside institution for 2 years prior to presentation. Diffuse pigmentation was noted in the angle, on the intraocular lens implant, and in the vitreous without clear demonstration of a mass on ultrasound biomicroscopy. Workup for metastatic cutaneous melanoma was negative. Histopathological examination of the enucleated eye revealed a mixed cell type iris ring melanoma with diffuse intraocular involvement. Gene expression profiling (GEP) revealed a class 2 molecular signature indicating a very high risk for metastases. Unilateral glaucoma presenting with marked pigmentation in the anterior chamber angle should be managed as melanoma until proven otherwise. Iris ring melanomas are known to have an aggressive clinical course, and recent molecular analyses indicate that they are likely primarily GEP class 2 with a very poor prognosis, similar to the majority of ciliary body melanomas.

Study of Unilateral Retinoblastoma With and Without Histopathologic High-Risk Features and the Role of Adjuvant Chemotherapy: A Children's Oncology Group Study

PURPOSE

To prospectively determine the prevalence of high-risk histopathologic features (HRFs) in patients with unilateral retinoblastoma who undergo enucleation and to evaluate the role of chemotherapy in preventing recurrences.

PATIENTS AND METHODS

Children newly diagnosed with enucleated unilateral retinoblastoma were enrolled prospectively. After central histopathology review, patients with specific HRFs received chemotherapy; others were observed. Primary end points were event-free survivals (EFS).

RESULTS

Of the 331 patients enrolled during 2005 to 2010, 321 eligible patients had central histopathologic review. Discordance between central review and contributing institutions occurred in 23% of patients with HRFs and in 17% of patients without HRFs. Postlaminar optic nerve involvement was present in 53 patients; 42 had massive posterior uveal invasion (≥ 3 mm); 15 had concomitant peripapillary 3 mm or greater choroid and postlaminar optic nerve involvement; and 15 had focal (< 3 mm) choroidal concomitant with lamina or prelamina optic nerve involvement. Two-year EFS for patients with HRFs requiring adjuvant chemotherapy was 0.96 (95% CI, 0.89 to 0.98), and 2-year EFS for patients without HRFs for which observation was indicated was 0.99 (95% CI, 0.96 to 1.0). The 2-year EFS for all patients was 0.98 (95% CI, 0.96 to 0.99).

CONCLUSION

Adequate handling and interpretation of histopathology of eyes with retinoblastoma is necessary to assign metastatic risk. Concomitant less than 3 mm choroidal and any prelaminar/laminar optic nerve invasion show no recurrence and may warrant no adjuvant chemotherapy. In contrast, concomitant greater than 3 mm peripapillary choroidal invasion and 1.5 mm or greater of postlaminar optic nerve invasion have the poorest outcomes, supporting the need for a more intensive adjuvant chemotherapy regimen for this subgroup. Strict criteria for adjuvant therapy may improve outcomes of children who undergo enucleation at diagnosis and may avoid unnecessary adjuvant chemotherapy for those who are not at risk for recurrence.

Pathologic Markers Determining Prognosis in Patients With Treated or Healing Giant Cell Arteritis

PURPOSE

To provide quantitative evidence linking the CD68 (cluster of differentiation 68)+ macrophage marker found on temporal artery biopsies (TABs) with disease prognosis.

DESIGN

Retrospective, cross-sectional study.

METHODS

We examined 42 consecutive patients who had undergone unilateral TABs at a single hospital in 2015. Clinical data, laboratory data, and histopathologic features of TABs were recorded. Inclusion criteria were clinical diagnosis of giant cell arteritis (GCA) with TAB performed at the same center. CD68 immunohistochemistry was used to label macrophages in the TABs. Primary outcome was multiple logistic regression and bivariate comparisons to measure the association between CD68+ cells per histologic section with placement on immunomodulatory therapy (IMT).

RESULTS

Twenty seven patients were female (64%), with a mean age of 72 (standard deviation [SD.] ±7.7). Eleven patients (26%) were placed on IMT, 17 (40%) had disease recurrence during steroid taper, and 25 (60%) were referred to rheumatology. Of 42 biopsies, 35 underwent staining with CD68 to confirm active inflammation in suspicious, but not diagnostic, specimens. Patients eventually placed on IMT had increased CD68+ cells per slice compared to those not on IMT (median 5.00 [25th-75th quartile 2.00-7.15] vs 1.21 [0.38-2.57], P = .031, respectively). A receiver operating characteristic (ROC) curve demonstrates that 2.17 CD68+ cells/slice predicts placement on IMT with an odds ratio of 1.54 (95% confidence interval 1.02-2.33, P = .038).

CONCLUSIONS

Patients refractory to initial steroid tapers and those eventually placed on IMT had increased CD68 cells per section. CD68+ macrophages and their location on the internal elastic lamina may predict disease severity in patients with presumed GCA. Our results suggest that this marker may expedite patient triaging to alternate treatment to the usual steroid therapy.

Genomic cfDNA Analysis of Aqueous Humor in Retinoblastoma Predicts Eye Salvage: The Surrogate Tumor Biopsy for Retinoblastoma

Tumor-derived cell-free DNA (cfDNA) has biomarker potential; therefore, this study aimed to identify cfDNA in the aqueous humor (AH) of retinoblastoma eyes and correlate somatic chromosomal copy-number alterations (SCNA) with clinical outcomes, specifically eye salvage. AH was extracted via paracentesis during intravitreal injection of chemotherapy or enucleation. Shallow whole-genome sequencing was performed using isolated cfDNA to assess for highly recurrent SCNAs in retinoblastoma including gain of 1q, 2p, 6p, loss of 13q, 16q, and focal MYCN amplification. Sixty-three clinical specimens of AH from 29 eyes of 26 patients were evaluated; 13 eyes were enucleated and 16 were salvaged (e.g., saved). The presence of detectable SCNAs was 92% in enucleated eyes versus 38% in salvaged eyes (P = 0.006). Gain of chromosome 6p was the most common SCNA found in 77% of enucleated eyes, compared with 25% of salvaged eyes (P = 0.0092), and associated with a 10-fold increased odds of enucleation (OR, 10; 95% CI, 1.8-55.6). The median amplitude of 6p gain was 1.47 in enucleated versus 1.07 in salvaged eyes (P = 0.001). The presence of AH SCNAs was correlated retrospectively with eye salvage. The probability of ocular salvage was higher in eyes without detectable SCNAs in the AH (P = 0.0028), specifically 6p gain. This is the first study to correlate clinical outcomes with SCNAs in the AH from retinoblastoma eyes, as such these findings indicate that 6p gain in the aqueous humor is a potential prognostic biomarker for poor clinical response to therapy.Implications: The correlation of clinical outcomes and SCNAs in the AH identified in the current study requires prospective studies to validate these finding before SCNAs, like 6p gain, can be used to predict clinical outcomes at diagnosis. Mol Cancer Res; 16(11); 1701-12. ©2018 AACR.

Perineurial-like Cells and EMA Expression in the Suprachoroidal Region of the Human Eye

The suprachoroidal region of the eye comprises vascular channels, melanocytes, and thin fibroblasts with elongated cytoplasm that are positioned directly adjacent to the densely collagenous sclera. Morphological similarities between these suprachoroidal fibroblasts and arachnoid cells and perineurial cells have been recognized, but whether these fibroblasts have a perineurial cell-like immunophenotype is not known. To further examine the relationship of these three cell types, we investigated the comparative expression of epithelial membrane antigen (EMA), the tight junction protein claudin-1, glucose transporter-1 (Glut-1), and CD34 in suprachoroidal fibroblasts, arachnoid of the optic nerve sheath, and perineurium of ciliary nerves in eight human eye specimens. Granular, diffuse, and cytoplasmic EMA expression was seen in suprachoroidal fibroblasts, but this was not contiguous with the similar pattern of EMA expression in adjacent perineurium and arachnoid. CD34 expression in suprachoroidal fibroblasts was also seen, similar to arachnoid and perineurium. Claudin-1 and Glut-1 were not consistently expressed in suprachoroidal fibroblasts, distinguishing them from perineurial cells in particular and suggesting that these fibroblasts do not arise directly from adjacent arachnoid or perineurium. Nonetheless, the overlapping morphology and protein expression suggest phenotypic similarities in these cells that protect and support adjacent retina, optic nerve, and peripheral nerve.

Perineural spread of basosquamous carcinoma to the orbit, cavernous sinus, and infratemporal fossa

Basosquamous carcinoma is a rare, highly aggressive variant of basal cell carcinoma with elevated rates of recurrence, perineural invasion, and metastasis. We describe a patient who presented with unilateral complete ophthalmoplegia, ptosis, optic neuropathy, and trigeminal neuropathy due to perineural intracranial invasion of nasal basosquamous carcinoma via the sphenopalatine fossa to the cavernous sinus, orbit, and infratemporal fossa. To our knowledge, this is the first reported case of basosquamous carcinoma with perineural invasion involving the cavernous sinus in the English language ophthalmic literature. Physicians should be aware of the diagnostic features, clinical challenges and aggressive nature of basosquamous carcinoma, a rare diagnosis that can lead to significant morbidity/mortality when left unrecognized.

Characterizing Anterior Segment OCT Angle Landmarks of the Trabecular Meshwork Complex

PURPOSE

To identify the presence or absence of 3 identifiable landmarks: trabecular meshwork (TM), Schlemm's canal (SC), and a novel landmark termed the band of extracanalicular limbal lamina (BELL), which is a landmark adjacent to SC visible on anterior segment (AS) OCT. These landmarks also were analyzed pathologically to identify all 3 landmarks.

DESIGN

Retrospective review.

PARTICIPANTS

One eye per participant from prior institutional review board-approved studies in which AS OCT imaging was performed.

METHODS

Horizontal images from 2-dimensional angle analysis scans using a CASIA SS-1000 (Tomey, Nagoya, Japan) AS OCT were evaluated by masked readers. Logistic regression was used to analyze the potential factors of age, gender, race, intraocular pressure, gonioscopy grade, angle location, and history or presence of surgery on the visibility of these structures. Pathologic correlation on 5 previously enucleated eyes also was performed.

MAIN OUTCOME MEASURES

Presence or absence of angle landmarks-TM, SC, and BELL-using Anterior Chamber Analysis and Interpretation software (ACAI, Houston, TX).

RESULTS

Three hundred three angles of 153 horizontal images were included in this study. The mean age was 51.5±16.0 years, with 98 women (64%) and 100 white persons (66%). The outer border of the BELL was observed in 288 angles (95%), TM was found in 220 angles (73%), and SC was seen in 120 angles (40%). The outer border of the BELL was more visible in white persons (P = 0.02) than Asians and in eyes with a Spaeth gonioscopy grade of E than those with a grade of A (P = 0.02). Both TM (P = 0.001) and SC (P = 0.001) were more visible in temporal angles (81% for TM, 49% for SC) than in nasal angles (64% for TM, 30% for SC). Additionally, SC was more visible in open angles (43%) than in narrow angles (27%; P = 0.02). These 3 structures were verified in a pathologic study.

CONCLUSIONS

We identified a novel AS OCT landmark adjacent to SC. This structure also was identified on pathologic samples from enucleated eyes. Further study is needed to determine the pathophysiologic relevance of these findings.

Proteolytic Degradation and Inflammation Play Critical Roles in Polypoidal Choroidal Vasculopathy

Polypoidal choroidal vasculopathy (PCV) is a common subtype of wet age-related macular degeneration in Asian populations, whereas choroidal neovascularization is the typical subtype in Western populations. The cause of PCV is unknown. By comparing the phenotype of a PCV mouse model expressing protease high temperature requirement factor A1 (HTRA1) in retinal pigment epithelium with transgenic mice expressing the inactive HTRA1S328A, we showed that HTRA1-mediated degradation of elastin in choroidal vessels is critical for the development of PCV, which exhibited destructive extracellular matrix remodeling and vascular smooth muscle cell loss. Compared with weak PCV, severe PCV exhibited prominent immune complex deposition, complement activation, and infiltration of inflammatory cells, suggesting inflammation plays a key role in PCV progression. More important, we validated these findings in human PCV specimens. Intravitreal delivery of an HTRA1 inhibitor (DPMFKLboroV) was effective (36% lesion reduction; P = 0.009) in preventing PCV initiation but ineffective in treating existing lesions. Anti-inflammatory glucocorticoid was effective in preventing PCV progression but ineffective in preventing PCV initiation. These results suggest that PCV pathogenesis occurs through two stages. The initiation stage is mediated by proteolytic degradation of extracellular matrix proteins attributable to increased HTRA1 activity, whereas the progression stage is driven by inflammatory cascades. This study provides a basis for understanding the differences between PCV and choroidal neovascularization, and helps guide the design of effective therapies for PCV.

Juvenile Xanthogranuloma in a Pediatric Patient with Langerhans Cell Histiocytosis

Purpose

To report a case of juvenile xanthogranuloma that simulated a chalazion and to discuss the association between juvenile xanthogranuloma and Langerhans cell histiocytosis.

Method

Case report and review of literature.

Results

A 13-year-old boy with a prior history of Langerhans cell histiocytosis was referred to our clinic for a possible chalazion. The patient had undergone treatment for Langerhans cell histiocytosis 10 years prior. The patient underwent an excisional biopsy. Histopathology revealed a proliferation of histiocytes and lymphocytes with Touton giant cells, consistent with a diagnosis of juvenile xanthogranuloma.

Conclusions

Though the relationship between Langerhans cell histiocytosis and juvenile xanthogranuloma has yet to be fully elucidated, juvenile xanthogranuloma should be included in the differential diagnosis for any former Langerhans cell histiocytosis patient presenting with a new cutaneous lesion.

Atypical Retinal Pigment Epithelial Hyperplasia and Glial Proliferation Masquerading as Progressive Recurrent Retinoblastoma: A Case Report Review and Clinicopathologic Correlation

Background

Recurrences of retinoblastoma tumors, particularly scar recurrences, are a common phenomenon in the management of this cancer. Consolidative treatment with laser and cryotherapy are required for local control of disease. It is known that consolidative therapy can induce retinal pigment epithelium (RPE) hyperplasia and gliosis. Herein we report extensive RPE hyperplasia and gliosis during laser therapy for a focal scar recurrence, which presented as a progressive retinal opacification mimicking active retinoblastoma.

Method

This is a retrospective case review.

Results

A 2-month-old premature male was diagnosed with sporadic bilateral retinoblastoma (International Intraocular Retinoblastoma Classification [IIRC] group B in the right eye and IIRC group A in the left eye). The patient underwent laser therapy for a focal recurrence which demonstrated a white lesion during therapy and was subsequently enucleated. While there was a focal recurrence and infiltration of the retina (seen both on optical coherence tomography and histopathologic section), the majority of the white, progressive lesion was from extensive RPE hyperplasia and gliosis secondary to laser therapy.

Conclusion

Clinicopathologic correlation of the active recurrence and adjacent gliosis is demonstrated.

Vitreous Seeds in Retinoblastoma: Clinicopathologic Classification and Correlation

PURPOSE

A recent classification scheme for retinoblastoma vitreous seeds has shown promise in predicting treatment response. For the first time, we correlate this clinical classification scheme with its histopathologic features.

DESIGN

Retrospective review.

PARTICIPANTS

Enucleated eyes received at the pathology department of the Retinoblastoma Center of Houston from 2010 to 2015.

METHODS

Macroscopic photographs of the enucleated eyes of patients with retinoblastoma were analyzed to select those with vitreous seeds. Cases with adequate material for clinicopathologic correlation were selected for further analysis, and clinical photographs were reviewed. Routine histopathologic slides were reviewed and compared with the clinical and macroscopic photographs. Seeds were classified as type 1 ("dust"), type 2 ("sphere"), or type 3 ("cloud"). To confirm the presence of macrophages, CD68 immunohistochemical staining was used. Synaptophysin was used to stain retinoblastoma cells.

MAIN OUTCOME MEASURES

To correlate clinical vitreous seed type with histopathologic features.

RESULTS

A total of 14 eyes with adequate amounts of tumor seeds along with clinical and macroscopic photographic correlation were selected from a total of 138 eyes reviewed. Type 1 seeds consisted of individual viable tumor cells and scattered macrophages. Type 2 seeds consisted of 2 submorphologies: spheres with viable cells throughout and spheres with an outer rim of viable cells but necrotic cells centrally. Type 3 seeds were composed of more than 90% necrotic material admixed with few macrophages and viable cells at their outer rim. Untreated (8/14) and previously treated (6/14) eyes showed similar histopathologic features for each type of seeds. Treated eyes had more type 1 and 3 seeds.

CONCLUSIONS

We provide the first histopathologic correlation of the clinical classification scheme for vitreous seeds in retinoblastoma. "Dust" is formed by scattered single cells alternating with macrophages. "Spheres" with translucent centers contain multiple layers of viable tumor cells that shed single cells and may be more clinically aggressive. "Cloud" seeds are mostly composed of necrotic material, explaining their lack of therapeutic response. Pretreated eyes showed tumor seeds morphologically similar to untreated eyes. Knowledge of the underlying histopathology of vitreous seed types is a fundamental component of classification and may aid in understanding clinical response to treatment.

Microsporidial Stromal Keratitis: Successful Treatment with Topical Voriconazole and Oral Itraconazole

We report a case of microsporidial stromal keratitis successfully treated with topical voriconazole and oral itraconazole. A 30-year-old Hispanic male construction worker who wears contacts lenses presented with left eye erythematous, epiphora, and mild pain increasing over few days after failing previous antibiotics treatment. His best corrected visual acuity in the left eye was count fingers at three feet, and the slit lamp examination showed 3+ conjunctival injection, a circular central corneal ulcer 3.2 mm in diameter, stromal thinning, and an anterior chamber with white cells, flair, and 0.1 mm hypopyon. A cornea punch biopsy identified microsporidial organisms with some features suggestive of Vittaforma corneae. After treatment with topical voriconazole and oral itraconazole for eight weeks, the patient had complete resolution with no recurrence for over 12 months of follow-up. To our knowledge, this is the first reported case of successful treatment of microsporidial stromal keratitis with antifungals.

Anterior chamber cholesterolosis in a patient with retinoblastoma

Anterior chamber cholesterolosis is a rare phenomenon typically associated with non-neoplastic conditions such as hyphema or Coats disease; it has never been reported to be associated with intraocular malignancy. We report a case of anterior chamber cholesterolosis presenting in the setting of retinoblastoma and discuss clinical features relevant for its differentiation from Coats disease.

Late Presentation of Retinoblastoma in a Teen with Aicardi Syndrome

BACKGROUND/AIMS

Retinoblastoma (Rb) generally presents in children <8 years of age. Aicardi syndrome (AS) is a congenital, neurodevelopmental disorder that has been associated with various ophthalmic abnormalities, but no reports have related it to a delayed presentation of Rb. This report describes the late presentation of Rb in a teenage patient with AS and suggests modifications in ophthalmic screening to facilitate early detection.

METHODS

A chart review was conducted of a patient with AS. We examined the ophthalmic history, fundus images and B-scan ultrasonography. Histopathological analysis was conducted on globe sections.

RESULTS

The patient's ophthalmic history was consistent with normal findings of AS: fundus images and B-scan ultrasonography revealed chorioretinal lacunae and an area of retinal detachment, respectively. The patient presented with chronic irritation and mydriasis of the blind left eye. This was enucleated as treatment. Histopathology revealed a focally differentiated Rb. Immunohistochemistry demonstrated that the tumor cells were positive for synaptophysin and negative for the wild-type Rb protein, and a high Ki-67 proliferation index was shown.

CONCLUSION

Our patient was diagnosed with Rb at age 16. AS has been associated with numerous ophthalmic findings, but this is the first report relating it to a late Rb presentation. Meticulous ophthalmic examinations should be considered through the teenage years and early adulthood of AS patients.

Expression of Angiogenic Factors in Invasive Retinoblastoma Tumors Is Associated With Increase in Tumor Cells Expressing Stem Cell Marker Sox2

Context

Progression of retinoblastoma is associated with increased tumor angiogenesis. However, a clear relationship between the expression of angiogenic markers in specific regions of the tumor and tumor progression has not been established. This study investigates the association between angiogenic factors in retinoblastomas with choroidal and/or optic nerve invasion (high-risk/invasive retinoblastoma) and expression of Sox2, a stem cell marker.

Objective

To investigate the association between the expression of angiogenic factors and markers of tumor invasiveness, such as the stem cell marker Sox2, in retinoblastoma tissues.

Design

Immunohistochemistry was used to evaluate coexpression of the angiogenic growth factors vascular endothelial growth factor A (VEGF-A), VEGF receptor 2 (VEGFR-2), and endoglin (CD105); markers of glial differentiation (vimentin and glial fibrillary acidic protein); and a neural stem cell marker (Sox2). Expression was assessed in nonneoplastic and neoplastic ocular tissues collected from enucleated eyes of patients with retinoblastoma. During qualitative data interpretation, evaluating pathologists were masked to patient grouping.

Results

Expression of VEGF-A and VEGFR-2 in noninvasive (non–high-risk feature) retinoblastoma tumors was lower than in the invasive, or high-risk feature tumors. Moreover, our data indicate that the tumor cells, and not the surrounding stroma, secrete VEGF-A and that angiogenesis is mostly localized to the iris. Finally, our data showed that the expression of the neural stem cell marker Sox2 is associated with eyes with increased VEGF-A expression and tumor invasiveness.

Conclusions

Increased expression of angiogenic factors, with a concomitant increase in expression of the stem cell marker Sox2 observed in retinoblastoma tissues, may partially explain the aggressiveness of these tumors. The complex interaction of angiogenic and stem cell–related pathways in these tumors, especially in high-risk feature retinoblastoma, suggests that targeting tumor cells capable of secreting vasculogenic factors, as well as proangiogenic genes and signaling pathways, may be necessary for development of effective antimetastatic retinoblastoma drugs.

Levamisole-Induced Vasculitis: A Characteristic Cutaneous Vasculitis Associated With Levamisole-Adulterated Cocaine

Levamisole-induced vasculitis is a characteristic cutaneous vasculitis syndrome associated with the use of levamisole-adulterated cocaine. Patients will typically present with a painful, purpuric rash in a retiform or stellate pattern with or without central necrosis involving the extremities, trunk, nasal tip, digits, cheeks, and/or ears. A history of cocaine abuse can be elicited. Histologic features include microvascular thrombi and/or leukocytoclastic vasculitis involving small vessels of the superficial and deep dermis. Epidermal involvement is variably seen. Laboratory findings include leukopenia, neutropenia (including agranulocytosis), elevated erythrocyte sedimentation rate, normal coagulation studies, and positive autoantibodies including perinuclear and cytoplasmic antineutrophil cytoplasmic antibodies, antinuclear antibody, and lupus anticoagulant. Differential diagnosis includes other microscopic vasculitides, and clinical and laboratory correlation with histologic findings is essential. Lesions typically resolve with the cessation of cocaine use. Because of the treatment implications and rising incidence of this entity, rapid and accurate diagnosis is essential.

Transarterial Onyx Embolization of an Orbital Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) is an uncommon mesenchymal neoplasm sometimes found in the orbit. We report a case of an aggressive orbital SFT with enlarged feeding vessels that was successfully resected immediately after transarterial embolization with Onyx (ethylene vinyl alcohol copolymer). To our knowledge, this is the first report showing the histopathology of Onyx embolization material in an orbital SFT.

Inflamed conjunctival nevi: histopathological criteria

Inflamed conjunctival nevi (ICN) may suggest malignancy because of their rapid growth and atypical histology. The objective of this study was to characterize the diagnostic features of ICN. A retrospective, nonrandomized study of 13 patients with ICN was conducted. A scoring method was developed based on histology and immunopathological parameters. The presence of epithelial solid or cystic inclusions and the preservation of goblet cells are consistent with a benign melanocytic lesion. Periodic acid-Schiff stain and immunohistochemistry to identify the epithelial component prove helpful in the differential diagnosis for melanoma. Polyclonal lymphoid infiltrate and benign cytological features of ICN exclude a diagnosis of lymphoma. Despite the presence of immunoglobulin 4-positive plasma cells in the lesions, ICN does not meet the diagnostic criteria for immunoglobulin 4-related disease. Most patients with ICN are young. The treatment for ICN is complete excision, and the prognosis is excellent.

Selective Pathology Fellowships: Diverse, Innovative, and Valuable Subspecialty Training

Context.—Although selective pathology fellowships have a long-standing history of developing trainees with advanced expertise in specific areas of pathology other than those of the American Board of Pathology–certified subspecialties, the widespread interest in this training continues to grow.

Objective.—To describe the historical background and current status of selective pathology fellowships, and to provide examples of 3 programs. In addition, Accreditation Council for Graduate Medical Education (ACGME)–accredited programs and nonaccredited programs in Selective Pathology are compared.

Data Sources.—ACGME data banks and publicly available online materials were used. Program directors of the fellowships examples in this paper provided program-specific information. Additionally, an online survey of the program directors and program coordinators of ACGME-accredited programs and nonaccredited programs in selective pathology was performed.

Conclusions.—There are currently 76 ACGME-accredited selective pathology programs. The programs are distributed between 3 major categories: surgical pathology, focused anatomic pathology, and focused clinical pathology. Although the vast majority of programs are concerned that their funding source may be cut in the next 3 years, most programs will not change the number of fellowship positions in their programs. Program requirements devoted specifically and solely to selective pathology have been developed and are in effect. The value of this training is recognized not only by pathologists, but by clinicians as well, in both academia and private practice. Importantly, the diversity and innovation inherent in selective pathology allow these programs to adeptly address new subspecialty areas and technologic advances in the current and evolving practice of pathology.

Hemangioblastoma of the optic nerve producing bilateral optic tract edema in a patient with von Hippel-Lindau disease

BACKGROUND

The authors present a novel case of a hemangioblastoma of the optic nerve producing bilateral optic tract edema in a patient with von Hippel-Lindau disease (VHL). This is the only case in the literature documenting optic tract edema secondary to a hemangioblastoma of the optic nerve.

CASE DESCRIPTION

The patient was a 34-year-old female in whom this lesion was causing retro-orbital pain and proptosis. She had previously lost vision in the symptomatic eye secondary to a retinal hemangioblastoma. The optic nerve lesion was excised by sectioning the optic nerve both proximally and distally to the lesion. There were no complications and patient's symptoms resolved postoperatively. A follow-up magnetic resonance imaging (MRI) scan revealed complete excision of the mass and resolution of the optic tract edema.

CONCLUSION

Optic nerve hemangioblastomas in patients with VHL are rare, but are manageable with meticulous microneurosurgery and with appropriate patient expectations. This is the first known case of an optic nerve hemangioblastoma producing bilateral optic tract edema, which resolved after resection of the prechiasmal tumor. Hemangioblastoma should remain in the differential diagnosis of optic nerve tumors, especially in the setting of VHL.

Verrucous Cyst With Melanocytic and Sebaceous Differentiation: A Case Report and Review of the Literature

A 58-year-old woman presented with a cystic skin lesion. Microscopic examination showed an intradermal cyst lined by acanthotic squamous epithelium with squamous eddies and compact hyperkeratosis, and changes typical of verrucous lesions. Mature sebaceous cells and dendritic melanocytes were present as well. To our knowledge, this is the first report of a verrucous cyst with areas of sebaceous differentiation and melanocytes. Verrucous cysts are well-known, benign lesions with a clear histologic pattern. Histologically, they resemble verruca vulgaris with acanthosis, hypergranulosis, dense keratohyaline granules, and viral cytopathic effects seen. Until now, melanocytes and mature sebaceous cells in the cyst lining have not been reported. We do not feel that these findings alter the expected benign nature of this lesion. Instead, we report this case to suggest the possible adnexal embryonic origin, given the presence of sebaceous cells and dendritic melanocytes that support this histologic lineage in our specific case.

Immunoglobulin G4-positive Sclerosing Idiopathic Orbital Inflammation: New Neuro-ophthalmological Presentations

We report two rare cases of biopsy proven Immunoglobulin G4-related sclerosing orbital inflammation (IgG4SOI). The first case had intracranial involvement which, to our knowledge, is the first IgG4SOI case with serum cerebrospinal fluid abnormalities and the second case had an unusual presentation of a compressive optic neuropathy and systemic lymphadenopathy.

Embryonic retinal tumors in SV40 T-Ag transgenic mice contain CD133+ tumor-initiating cells

PURPOSE

Human retinoblastomas form during the proliferative phase of retina development and are caused by mutations that result in absent or functionally defective Rb protein. Similar tumors occur in mice only when multiple Rb gene family members are absent. We asked if retinal tumors can arise from an undifferentiated retinal cell. The tumor-initiating cells isolated from these tumors that formed in early embryonic murine retinas were characterized.

METHODS

Transgenic mice were created using a Pax6 promoter to target expression of SV40 large T-antigen (T-Ag) in the undifferentiated murine embryonic retina. T-Ag, which sequesters all Rb family proteins and p53, is expressed in the retina and lens by murine embryonic day 10 (E10) and tumors are observed by E12.5. A cell line that is adherent in serum-containing media and forms neurospheres in supplemented serum-free media was developed from retinal tumors isolated on postnatal day 7.

RESULTS

In all, 1.5% of attached cells form neurospheres when transferred to serum-free medium. All cultured cells express T-Ag, confirming that they derive from the original tumors; 0.5% of adherent cells express detectable levels of CD133. CD133+ FACS-sorted cells cultured in serum-free medium form 3-fold more neurospheres than do CD133- cells. Six of seven mice injected with CD133+ cells and one of seven mice injected with CD133- cells formed tumors during a 6-month period. Unlike primary adherent cells, primary and secondary tumors heterogeneously express markers of stem cells and differentiation similar to human retinoblastoma.

CONCLUSIONS

CD133+ tumor-initiating cells can originate from proliferating undifferentiated precursor cells.

Outcomes of integrating genetics in management of patients with retinoblastoma

OBJECTIVE

To present the outcome of a comprehensive team approach to provide genetic evaluation and testing for a large cohort of children diagnosed with retinoblastoma.

METHODS

The multidisciplinary team included pediatric oncologists, an ophthalmologist, an ophthalmic pathologist, a geneticist, and genetic counselors. Retrospective data from 8 years included 90 initial evaluations, of which 81 probands were diagnosed with retinoblastoma (34 bilateral and 47 unilateral) and 9 were evaluated because of a positive family history.

RESULTS

Genetic testing was accomplished equivalently in bilateral and unilateral cases in 51 of 81 patients (63%). In 5 of 30 patients (17%), with unilateral disease an RB1 mutation was identified in peripheral blood samples. In another 7 of 30 patients (23%), mutation analysis confirmed the occurrence of sporadic retinoblastoma. Overall, genetic testing of 48 at-risk family members from 21 families revealed 6 individuals positive and 42 negative for the familial mutation.

CONCLUSIONS

Our study emphasizes that genetics can be incorporated into the management plan of all retinoblastoma patients using a team approach to ensure timely evaluations and appropriate counseling. Genetic evaluations improved risk prediction for patients and family members as well as prevented overutilization of clinical screening tests, which had potential morbidity for relatives documented to not carry an RB1 mutation.

Intraocular lymphoma: diagnostic approach and immunophenotypic findings in vitrectomy specimens

CONTEXT

Diagnosis and classification of primary intraocular lymphoma can be challenging because of the sparse cellularity of the vitreous specimens.

OBJECTIVE

To classify and clinically correlate intraocular lymphoma according to the World Health Organization (WHO) classification by using vitrectomy specimens.

DESIGN

Clinical history, cytologic preparations, flow cytometry reports, and outcome of 16 patients diagnosed with intraocular lymphoma were reviewed.

RESULTS

The study group included 10 women and 6 men. The mean age of the patients was 63 years (range, 19-79 years). Eleven patients had central nervous system involvement and 6 patients had systemic involvement. All cases were adequately diagnosed and classified according to the WHO classification by using combination of cytologic preparations and 4-color flow cytometry with a limited panel of antibodies to CD19, CD20, CD5, CD10, and kappa and lambda light chains. The cases included 9 primary diffuse large B-cell lymphomas of the CNS type; 2 diffuse large B-cell lymphomas, not otherwise specified; 1 extranodal, low-grade, marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT); 1 precursor B-lymphoblastic lymphoma; and 3 peripheral T-cell lymphomas, not otherwise specified. Of note, all 11 cases of diffuse large B-cell lymphoma were CD10-. All the patients received systemic chemotherapy and radiation therapy. Only 4 patients were free of disease at last follow-up (range, 18 months to 8 years), with severe visual loss.

CONCLUSIONS

Intraocular lymphoma cases can be adequately classified according to the WHO classification. Diffuse large B-cell lymphoma, CD10- and most likely of non-germinal center B-cell-like subgroup, is the most common subtype of non-Hodgkin lymphoma in this site, in contrast to ocular adnexal lymphoma for which MALT lymphoma is the most common subtype.

Proceedings of the consensus meetings from the International Retinoblastoma Staging Working Group on the pathology guidelines for the examination of enucleated eyes and evaluation of prognostic risk factors in retinoblastoma

Retinoblastoma is the most common intraocular malignant childhood tumor in need of prospective clinical trials to address important unanswered questions about biology, treatment, and prognostic factors. Currently, there is controversy about the definitions for choroidal invasion and an inconsistency in the handling of eyes with retinoblastoma. The International Retinoblastoma Staging Working Group (IRSWG) composed of 58 participants from 24 countries on 4 continents had a series of Internet meetings to discuss the staging and tissue handling guidelines to reach consensus for adequate processing, establishing definitions of histopathologic risk factors, and reporting of enucleated eyes with retinoblastoma to serve as the basis for clinical trials and studies to validate the proposed criteria. The meetings were facilitated by the International Outreach Program of the St. Jude Children's Research Hospital through Cure4Kids. The retinoblastoma guidelines from the Children's Oncology Group, the French Society for Pediatric Cancers, the Association of Directors of Anatomic and Surgical Pathology, and some published data were the basis for this consensus document. Discussions of the feasibility, practicality, and efficacy of the guidelines and criteria resulted in this report. The consensus definitions reached included definition of massive choroidal invasion stated as a maximum diameter of invasive tumor focus of 3 mm or more that may reach the scleral tissue. Focal choroidal invasion is defined as a tumor focus of less than 3 mm and not reaching the sclera. Optic nerve invasion is classified as prelaminar, laminar, retrolaminar, or tumor at surgical margin, and the measurement of the depth of invasion should also be recorded. These guidelines also address handling of the enucleated eye with retinoblastoma in an efficient, practical, and feasible manner for a meaningful diagnosis. The consensus criteria reached by the IRSWG should be validated through prospective clinical trials and studies.

Treatment of invasive retinoblastoma in a murine model using an oncolytic picornavirus

Retinoblastoma, the most common intraocular malignancy of childhood, metastasizes by initial invasion of the choroid and the optic nerve. There is no effective treatment for metastatic retinoblastoma, especially when the central nervous system (CNS) is involved, and prevention of this complication is a treatment priority. Seneca Valley Virus (SVV-001) is a conditionally replication-competent picornavirus that is not pathogenic to normal human cells but can kill human retinoblastoma cells in vitro with an IC(50) of <1 viral particle (vp) per cell. A xenograft murine model of metastatic retinoblastoma was used to examine the therapeutic potential of SVV-001. Histopathologic analysis of ocular and brain tissues after a single tail vein injection of SVV-001 (1 x 10(13) vp/kg) showed effective treatment of choroid and ocular nerve tumor invasion (1 of 20 animals with invasive disease in the treated group versus 7 of 20 animals with invasive disease in the control group; P = 0.017) and prevention of CNS metastasis (0 of 20 animals with CNS metastatic disease in the treated group versus 4 of 20 animals with CNS disease in the control group; P = 0.036). There were no observed adverse events due to the virus in any of the treated animals. SVV-001 may be effective as a treatment of locally invasive and metastatic retinoblastoma.

Ocular clusterin expression in von Hippel-Lindau disease

PURPOSE

Clusterin is a multifunctional glycoprotein. Its mRNA is ubiquitously expressed, with high levels in von Hippel-Lindau (VHL) target organs such as the brain, liver, kidney, and adrenal medulla. Decreased clusterin secretion has been reported in renal cell carcinoma associated with VHL disease. The purpose of this study was to investigate ocular clusterin expression in VHL disease.

METHODS

This retrospective case series included nine eyes with retinal hemangioblastoma/hemangioma associated with VHL disease, one eye from a patient with a history of VHL disease and central nervous system hemangioblastomas but without ocular lesions, one surgically-excised optic nerve with optic nerve hemangioblastoma/hemangioma, and three normal control eyes. Ocular specimens were evaluated by routine histology, immunohistochemistry for clusterin expression, and molecular detection of clusterin transcripts within ocular VHL hemangioblastomas compared with normal tissue from the same eye using microdissection and quantitative real-time PCR.

RESULTS

All retinal hemangioblastoma were composed of typical VHL tumor cells admixed with small vascular channels as well as glial cells. Marked decrease of clusterin immunoreactivity was detected in all retinal hemangioblastoma and the optic nerve hemangioblastoma, whereas positive clusterin reactivity of the vascular and glial components was similar to that of normal retina. Quantitative real-time PCR analysis confirmed the decrease of clusterin mRNA in the VHL associated retinal hemangioblastoma and optic nerve hemangioblastoma in five cases.

CONCLUSIONS

Clusterin shows possible important functions in tumor suppression by the VHL gene product (pVHL) and the potential to be a novel biomarker in retinal hemangioblastoma associated VHL disease. Further investigation of clusterin may provide better understanding of retinal hemangioblastoma associated with VHL disease.

Inhibition of experimental corneal neovascularisation by bevacizumab (Avastin)

AIM

To evaluate the effect of topically administered bevacizumab (Avastin) on experimental corneal neovascularisation in rats.

METHODS

Silver nitrate sticks (75% silver nitrate, 25% potassium nitrate) were used to perform chemical cauterisation on the corneas of 16 eyes from 16 male Long Evans rats. For the following 7 days, the 10 eyes in the treatment group were instilled with bevacizumab 4 mg/ml drops twice daily, whereas the 6 eyes in the control group received placebo (normal saline drops twice daily). Digital photographs of the cornea were analysed to determine the area of cornea covered by neovascularisation as a percentage of the total corneal area.

RESULTS

In the bevacizumab-treated eyes, neovascularisation covered, on average, 38.2% (15.5%) (mean (SD)) of the corneal surface compared with 63.5% (5.0%) in the control group (p<0.02, Mann-Whitney U test).

CONCLUSION

Topically administered bevacizumab (Avastin) at a concentration of 4 mg/ml limits corneal neovascularisation following chemical injury in the male Long Evans rat model.

Modulation of adenoviral transduction in vitro and in vivo by hyaluronan and its receptor CD44

Adenovirus infection is a significant cause of ocular, respiratory, and gastrointestinal illness and can spread rapidly. Morbidity is considerable in immune-suppressed individuals and there is significant mortality. There are no effective therapies. During preclinical studies of adenoviral-mediated gene therapy for ocular disorders, we noticed a significant increase in transduction when the target cells were exposed to adenovirus in the presence of ocular vitreous. The vitreous is mainly comprised of water, collagen, and the large polysaccharide hyaluronan. In this paper, we report data that implicate hyaluronan in the adenoviral infectious process and show that interference with the interaction between hyaluronan and its cellular receptor CD44 can block adenovirus transduction in vitro and in vivo.

Tumor cell plasticity in uveal melanoma: microenvironment directed dampening of the invasive and metastatic genotype and phenotype accompanies the generation of vasculogenic mimicry patterns

The histological detection of laminin-rich vasculogenic mimicry patterns in human primary uveal melanomas is associated with death from metastases. We therefore hypothesized that highly invasive uveal melanoma cells forming vasculogenic mimicry patterns after exposure to a laminin-rich three-dimensional microenvironment would differentially express genes associated with invasive and metastatic behavior. However, we discovered that genes associated with differentiation (GDF15 and ATF3) and suppression of proliferation (CDKNa1/p21) were up-regulated in highly invasive uveal melanoma cells forming vasculogenic mimicry patterns, and genes associated with promotion of invasive and metastatic behavior such as CD44, CCNE2 (cyclin E2), THBS1 (thrombospondin 1), and CSPG2 (chondroitin sulfate proteoglycan; versican) were down-regulated. After forming vasculogenic mimicry patterns, uveal melanoma cells invaded only short distances, failed to replicate, and changed morphologically from the invasive epithelioid to the indolent spindle A phenotype. In human tissue samples, uveal melanoma cells within vasculogenic mimicry patterns assumed the spindle A morphology, and the expression of Ki67 was significantly reduced in adjacent melanoma cells. Thus, the generation of vasculogenic mimicry patterns is accompanied by dampening of the invasive and metastatic uveal melanoma genotype and phenotype and underscores the plasticity of these cells in response to cues from the microenvironment.