Uveal Melanoma Biopsy: A Review

Heterogeneity and molecular landscape of melanoma: implications for targeted therapy

Uveal cancer (UM) offers a complex molecular landscape characterized by substantial heterogeneity, both on the genetic and epigenetic levels. This heterogeneity plays a critical position in shaping the behavior and response to therapy for this uncommon ocular malignancy. Targeted treatments with gene-specific therapeutic molecules may prove useful in overcoming radiation resistance, however, the diverse molecular makeups of UM call for a patient-specific approach in therapy procedures. We need to understand the intricate molecular landscape of UM to develop targeted treatments customized to each patient's specific genetic mutations. One of the promising approaches is using liquid biopsies, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), for detecting and monitoring the disease at the early stages. These non-invasive methods can help us identify the most effective treatment strategies for each patient. Single-cellular is a brand-new analysis platform that gives treasured insights into diagnosis, prognosis, and remedy. The incorporation of this data with known clinical and genomics information will give a better understanding of the complicated molecular mechanisms that UM diseases exploit. In this review, we focused on the heterogeneity and molecular panorama of UM, and to achieve this goal, the authors conducted an exhaustive literature evaluation spanning 1998 to 2023, using keywords like "uveal melanoma, "heterogeneity". "Targeted therapies"," "CTCs," and "single-cellular analysis".

Pathological and Molecular Diagnosis of Uveal Melanoma

(1) Background: Uveal melanoma (UM) is a common malignant intraocular tumor that presents with significant genetic differences to cutaneous melanoma and has a high genetic burden in terms of prognosis. (2) Methods: A systematic literature search of several repositories on uveal melanoma diagnosis, prognosis, molecular analysis, and treatment was conducted. (3) Results: Recent genetic understanding of oncogene-initiation mutations in GNAQ, GNA11, PLCB4, and CYSLTR2 and secondary progression drivers of BAP1 inactivation and SF3B1 and EIF1AX mutations offers an appealing explanation to the high prognostic impact of adding genetic profiling to clinical UM classification. Genetic information could help better explain peculiarities in uveal melanoma, such as the low long-term survival despite effective primary tumor treatment, the overwhelming propensity to metastasize to the liver, and possibly therapeutic behaviors. (4) Conclusions: Understanding of uveal melanoma has improved step-by-step from histopathology to clinical classification to more recent genetic understanding of oncogenic initiation and progression.

Impact of tumour volume and treatment delay on the outcome after linear accelerator-based fractionated stereotactic radiosurgery of uveal melanoma

BACKGROUND/AIMS

Primary radiation therapy is used to treat malignant uveal melanoma (UM). We report our single-centre experience with fractionated radiosurgery (fSRS) with a linear accelerator (LINAC) after specific adaptation for small target volumes with HybridArc.

METHODS

From October 2014 to January 2020, 101 patients referred to Dessau City Hospital with unilateral UM underwent fSRS with 50 Gy given in five fractions on five consecutive days. Primary endpoints were local tumour control, globe preservation, metastasis and death. Potential prognostic features were analysed. Kaplan-Meier analysis, Cox proportional hazards model and linear models were used for calculations.

RESULTS

The median baseline tumour diameter was 10.0 mm (range, 3.0-20.0 mm), median tumour thickness 5.0 mm (range, 0.9-15.5 mm) and median gross tumour volume (GTV) 0.4 cm³ (range, 0.2-2.6 cm³). After a median follow-up of 32.0 months (range, 2.5-76.0 months), 7 patients (6.9%) underwent enucleation: 4 (4.0%) due to local recurrence and 3 (3.0%) due to radiation toxicities, and 6 patients (5.9%) revealed tumour persistence with a GTV exceeding 1.0 cm³. Of 20 patients (19.8%) who died, 8 (7.9%) were tumour-related deaths. Twelve patients (11.9%) suffered from distant metastasis. GTV showed an impact on all endpoints, and treatment delay was associated with reduced odds of eye preservation.

CONCLUSION

LINAC-based fSRS with static conformal beams combined with dynamic conformal arcs and discrete intensity-modulated radiotherapy results in a high tumour control rate. The tumour volume is the most robust physical prognostic marker for local control and disease progression. Avoiding treatment delay improves outcomes.

Evaluation of Circulating Tumor DNA as a Liquid Biomarker in Uveal Melanoma

Purpose

Uveal melanoma (UM) has a high propensity to metastasize. Prognosis is associated with specific driver mutations and copy number variations (CNVs), but limited primary tumor tissue is available for molecular characterization due to eye-sparing irradiation treatment. This study aimed to assess the rise in circulating tumor DNA (ctDNA) levels in UM and evaluate its efficacy for CNV-profiling of patients with UM.

Methods

In a pilot study, we assessed ctDNA levels in the blood of patients with UM (n = 18) at various time points, including the time of diagnosis (n = 13), during fractionated stereotactic radiotherapy (fSRT) treatment (n = 6), and upon detection of metastatic disease (n = 13). Shallow whole-genome sequencing (sWGS) combined with in silico size-selection was used to identify prognostically relevant CNVs in patients with UM (n = 26) from peripheral blood retrieved at the time of diagnosis (n = 9), during fSRT (n = 5), during post-treatment follow-up (n = 4), metastasis detection (n = 6), and metastasis follow-up (n = 4).

Results

A total of 34 patients had blood analyzed for ctDNA detection (n = 18) and/or CNV analysis (n = 26) at various time points. At the time of diagnosis, 5 of 13 patients (38%) had detectable ctDNA (median = 0 copies/mL). Upon detection of metastatic disease, ctDNA was detected in 10 of 13 patients (77%) and showed increased ctDNA levels (median = 24 copies/mL, P < 0.01). Among the six patients analyzed during fSRT, three (50%) patients had detectable ctDNA at baseline and three of six (50%) patients had undetectable levels of ctDNA. During the fSRT regimen, ctDNA levels remained unchanged (P > 0.05). The ctDNA fractions were undetectable to low in localized disease, and sWGS did not elucidate chromosome 3 status from blood samples. However, in 7 of 10 (70%) patients with metastases, the detection of chromosome 3 loss corresponded to the high metastatic-risk class.

Conclusions

The rise in ctDNA levels observed in patients with UM harboring metastases suggests its potential utility for CNV profiling. These findings highlight the potential of using ctDNA for metastasis detection and patient inclusion in therapeutic studies targeting metastatic UM.

Quantitative Biomarkers Derived from a Novel, Contrast-Free Ultrasound, High-Definition Microvessel Imaging for Differentiating Choroidal Tumors

Angiogenesis has an essential role in the de novo evolution of choroidal melanoma as well as choroidal nevus transformation into melanoma. Differentiating early-stage melanoma from nevus is of high clinical importance; thus, imaging techniques that provide objective information regarding tumor microvasculature structures could aid accurate early detection. Herein, we investigated the feasibility of quantitative high-definition microvessel imaging (qHDMI) for differentiation of choroidal tumors in humans. This new ultrasound-based technique encompasses a series of morphological filtering and vessel enhancement techniques, enabling the visualization of tumor microvessels as small as 150 microns and extracting vessel morphological features as new tumor biomarkers. Distributional differences between the malignant melanomas and benign nevi were tested on 37 patients with choroidal tumors using a non-parametric Wilcoxon rank-sum test, and statistical significance was declared for biomarkers with p-values < 0.05. The ocular oncology diagnosis was choroidal melanoma (malignant) in 21 and choroidal nevus (benign) in 15 patients. The mean thickness of benign and malignant masses was 1.70 ± 0.40 mm and 3.81 ± 2.63 mm, respectively. Six HDMI biomarkers, including number of vessel segments (p = 0.003), number of branch points (p = 0.003), vessel density (p = 0.03), maximum tortuosity (p = 0.001), microvessel fractal dimension (p = 0.002), and maximum diameter (p = 0.003) exhibited significant distributional differences between the two groups. Contrast-free HDMI provided noninvasive imaging and quantification of microvessels of choroidal tumors. The results of this pilot study indicate the potential use of qHDMI as a complementary tool for characterization of small ocular tumors and early detection of choroidal melanoma.

Coexistence of choroidal melanoma and rhegmatogenous retinal detachment: a case report and literature review

Introduction and importance

The simultaneous occurrence of rhegmatogenous retinal detachment (RRD) and choroidal melanoma is extremely rare, and diagnosis of choroidal melanoma in RRD patients is challenging. As a result, choroidal masses in RRD patients tend to be overlooked, resulting in delayed treatment. The authors report a rare case presenting with simultaneous choroidal melanoma and RRD, and the authors review the related literature.

Case presentation

A 45-year-old Thai man who presented with inferior RRD and choroidal elevation in the left eye was examined using fundoscopy and ultrasonography. The presumptive diagnosis was simultaneous RRD and haemorrhagic choroidal detachment (CD). Vitrectomy and external drainage were attempted but were unsuccessful in draining fluid from the presumed haemorrhagic CD. Although the retina was reattached, the choroidal elevation remained unchanged. After being lost to follow-up, the patient returned later with severe proptosis in the left eye. MRI findings suggested a presumptive diagnosis including choroidal melanoma and choroidal metastasis, which choroidal melanoma was later confirmed through histopathological examination after exenteration.

Clinical discussion

Important clinical clues were provided for distinguishing between choroidal melanoma and haemorrhagic CD in cases of coexisting RRD.

Conclusions

In the differential diagnosis of RRD with suspicious choroidal elevation, the possibility of the presence of choroidal melanoma should be considered. In particular, in cases where haemorrhagic CD fails to drain during surgery, the possibility of underlying choroidal melanoma should be investigated.

Multifocal choroidal melanoma: a clinicohistopathological correlation

A woman in her late 50s presented with on-and-off redness and diminution of vision in her left eye for 6 months. Her best corrected visual acuity was 20/40 in the right eye and hand motion in the left eye. Anterior segment examination revealed a greyish-white lesion extending from 3 to 6 o'clock hours posterior to the iris and protruding into the anterior chamber. Left eye B-scan ultrasonography showed a multifocal choroidal lesion, a smaller one involving the posterior pole, and a larger lesion involving the complete nasal quadrant and anteriorly extending to the ciliary body and iris. Fine-needle aspiration biopsy performed from the anterior lesion showed a possible neoplastic aetiology of melanocytic origin of the cells. Finally, the patient underwent left eye enucleation with a ball implant. Histopathological examination of the enucleated eye confirmed the final diagnosis of multifocal choroidal melanoma involving the adjacent ciliary body and iris.

Tumor-Associated Retinal Pigmentation in Choroidal Melanoma

PURPOSE

To report a previously unrecognized choroidal melanoma clinical feature termed tumor-associated retinal pigmentation (TARP) and determine any correlation with tumor biology.

DESIGN

Imaging and histologic analysis of a retrospective cohort of patients.

PARTICIPANTS

Patients with choroidal melanoma identified as having TARP on funduscopy at the Liverpool Ocular Oncology Centre (LOOC), United Kingdom, from January 2020 through January 2023.

METHODS

Clinical and imaging characteristics of patients diagnosed with choroidal melanoma and exhibiting TARP on fundoscopy were documented. Details of these choroidal melanomas were collated and correlated with histopathology and molecular genetic reports. The chromosome 3 status of each tumor was assessed. In enucleated samples, immunostaining was undertaken to determine the nature of the TARP using specific markers (CD68 and MelanA).

MAIN OUTCOME MEASURES

Features of TARP on widefield fundus color imaging, fundus autofluorescence (FAF), and OCT were described. Tumor chromosome 3 status and the immunoprofile of the TARP also were collated.

RESULTS

Tumor-associated retinal pigmentation had a prevalence rate of 7.47 per 100 cases of choroidal melanoma at the LOOC. Twenty-three eyes with TARP were analyzed, with a mean age of 71.4 years (range, 51-88 years). The median largest basal diameter was 16.10 mm (range, 9.17-21.32 mm), and the mean tumor thickness was 8.04 mm (range, 1.40-13.80 mm). Tumor-associated retinal pigmentation was observed on widefield color fundus imaging, with hypofluorescence on FAF images and represented hyperreflective foci located in intraretinal and subretinal spaces on OCT scans. Seventeen patients (73.9%) underwent enucleation, and 6 patients (26.1%) underwent globe-sparing treatment. Molecular genetic analysis of 20 choroidal melanomas (after enucleation or radiotherapy biopsy) revealed monosomy 3 in 18 tumors (90%). Immunostaining of the TARP in enucleated eyes showed CD68+ melanophages in all 17 patients appearing as scattered cells and aggregates; MelanA findings were negative.

CONCLUSIONS

Tumor-associated retinal pigmentation represents tumor-associated macrophages, not melanocytes, within intraretinal and subretinal spaces of larger choroidal melanomas. Radiation treatments need not involve this area in the treatment plan, minimizing radiation-related complications. This novel clinical sign seems to be linked to tumors of high metastatic-risk clinical and genetic characteristics, with a preponderance having monosomy 3 anomalies.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Assessment of Different Circulating Tumor Cell Platforms for Uveal Melanoma: Potential Impact for Future Routine Clinical Practice

Liquid biopsy and circulating tumor cell (CTC) screening has gained interest over the last two decades for detecting almost all solid malignancies. To date, the major limitation in terms of the applicability of CTC screening in daily clinical practice is the lack of reproducibility due to the high number of platforms available that use various technologies (e.g., label-dependent versus label-free detection). Only a few studies have compared different CTC platforms. The aim of this study was to compare the efficiency of four commercially available CTC platforms (Vortex (VTX-1), ClearCell FX, ISET, and Cellsearch) for the detection and identification of uveal melanoma cells (OMM 2.3 cell line). Tumor cells were seeded in RPMI medium and venous blood from healthy donors, and then processed similarly using these four platforms. Melan-A immunochemistry was performed to identify tumor cells, except when the Cellsearch device was used (automated identification). The mean overall recovery rates (with mean recovered cells) were 39.2% (19.92), 22.2% (11.31), 8.9% (4.85), and 1.1% (0.20) for the ISET, Vortex (VTX-1), ClearCell FX, and CellSearch platforms, respectively. Although paramount, the recovery rate is not sufficient to assess a CTC platform. Other parameters, such as the purpose for using a platform (diagnosis, genetics, drug sensitivity, or patient-derived xenograft models), reproducibility, purity, user-friendliness, cost-effectiveness, and ergonomics, should also be considered before they can be used in daily clinical practice and are discussed in this article.

Need for a Dedicated Ophthalmic Malignancy Clinico-Biological Biobank: The Nice Ocular MAlignancy (NOMA) Biobank

Ophthalmic malignancies include various rare neoplasms involving the conjunctiva, the uvea, or the periocular area. These tumors are characterized by their scarcity as well as their histological, and sometimes genetic, diversity. Uveal melanoma (UM) is the most common primary intraocular malignancy. UM raises three main challenges highlighting the specificity of ophthalmic malignancies. First, UM is a very rare malignancy with an estimated incidence of 6 cases per million inhabitants. Second, tissue biopsy is not routinely recommended due to the risk of extraocular dissemination. Third, UM is an aggressive cancer because it is estimated that about 50% of patients will experience metastatic spread without any curative treatment available at this stage. These challenges better explain the two main objectives in the creation of a dedicated UM biobank. First, collecting UM samples is essential due to tissue scarcity. Second, large-scale translational research programs based on stored human samples will help to better determine UM pathogenesis with the aim of identifying new biomarkers, allowing for early diagnosis and new targeted treatment modalities. Other periocular malignancies, such as conjunctival melanomas or orbital malignancies, also raise specific concerns. In this context, the number of biobanks worldwide dedicated to ocular malignancies is very limited. The aims of this article were (i) to describe the specific challenges raised by a dedicated ocular malignancy biobank, (ii) to report our experience in setting up such a biobank, and (iii) to discuss future perspectives in this field.

Evaluation of optical coherence tomography (OCT) changes following transretinal tumour biopsy for choroidal melanoma

AIM

This study uses OCT imaging to examine morphological changes at the chorioretinal interface of the choroidal melanoma biopsy site over time.

SETTING

Liverpool Ocular Oncology Centre (LOOC), St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom.

METHODOLOGY

Retrospective analysis of all patients who underwent 25G vitrector-assisted transretinal biopsy for choroidal melanoma between 1st Jan 2017 and 31st Dec 2019. The biopsy procedure does not involve full vitrectomy, treatment of the retinal hole or tamponade. Patients routinely undergo OCT imaging over the tumour site at each follow up. Cases required a minimum of a baseline OCT and two consecutive post-operative OCT scans of adequate quality, overlying the biopsy site. All images were reviewed and graded by an ophthalmic specialist.

RESULTS

Fifty-one patients met the criteria for inclusion. OCT analysis identified 2 characteristic morphologies following transretinal biopsy -a choroidal plugging of biopsy site (47.0%), or a flat retinal hole (53.0%). Choroidal plugging morphologies tend to remain unchanged over time, whereas flat holes demonstrate greater variability and would more commonly seal over with atrophic retina (Fisher Exact Value = <0.01). 60.8% demonstrated vitreous plugging of the biopsy site.

CONCLUSION

OCT analysis has identified key morphological changes following transretinal choroidal melanoma biopsy. The morphologies identified may provide dynamic protective effects against vitreous flow into the subretinal space, accounting for low rates of retinal detachment despite the presence of an untreated iatrogenic retinal hole following transretinal biopsy.

Importance of Optical Coherence Tomography and Optical Coherence Tomography Angiography in the Imaging and Differentiation of Choroidal Melanoma: A Review

Simple Summary

Choroidal melanoma is a highly malignant intraocular neoplasm. It is the most prevalent intraocular tumor in adults and it derives from melanocytes; the liver is the most common site of its metastases. An early and noninvasive diagnosis is essential to enhance patients’ chances for early treatment. The OCT and OCTA-A are a noninvasive and noncontact methods used in the diagnostic process and support therapeutic decisions during control visits. These devices allow for detection and the real-time imaging of choroidal melanoma and its differentiation from metastasis and choroidal nevi. In addition to analyzing the currently utilized OCT and OCT-A methods, this review describes also the anatomy and imaging of specific vascular layers of the eye.

Abstract

Choroidal melanoma requires reliable and precise clinical examination and diagnosis to differentiate it from benign choroidal nevi. To achieve accurate diagnosis, as well as monitoring the progression of disease, various imaging modalities are used, including non-invasive optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). This review begins with a historical account of the development of OCT and OCTA and the methods of generation of images. This outlines the understanding of what OCT/OCTA images show, as well as how image artifacts arise. The anatomy and imaging of specific vascular layers of the eye are introduced. Then, anatomical aspects of choroidal melanoma, its diagnosis and differentiation from metastasis, and choroidal nevi are presented. The purpose of this review is to critically evaluate application of OCT and OCTA in the diagnosis of choroidal melanoma.

Integrated analysis reveals the dysfunction of signaling pathways in uveal melanoma

Background

Uveal melanoma (UM) is the most common primary intraocular malignancy with a strong tendency to metastasize. The prognosis is poor once metastasis occurs. The treatment remains challenging for metastatic UM, even though our understanding of UM has advanced, mostly because the complexity of the genetic and immunologic background has not been fully explored.

Methods

Single-cell sequencing data were acquired from a healthy dataset and three UM datasets. The differentially expressed genes between primary and metastatic UM in The Cancer Genome Atlas (TCGA) data were attributed to specific cell types and explained with functional annotation. The analysis for cell–cell communication was conducted by “CellChat” to understand the cell crosstalk among the cell clusters and to delineate the dysfunctional signaling pathways in metastatic UM. CCK-8, EdU and transwell assays were performed to verify the function of the genes of interest.

Results

We revealed aberrant signaling pathways with distinct functional statuses between primary and metastatic UM by integrating multiple datasets. The crucial signals contributing most to outgoing or incoming signaling of metastasis were identified to uncover the potential targeting genes. The association of these genes with disease risk was estimated based on survival data from TCGA. The key genes associated with proliferation and metastasis were verified.

Conclusions

Conclusively, we discovered the potential key signals for occurrence and metastasis of UM and provided a theoretical basis for potential clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09822-8.

Case Series: Presumed Choroidal Melanoma Diagnosis Expedited by Documented Growth on Serial Optical Coherence Tomography

SIGNIFICANCE

These cases highlight the importance of monitoring choroidal nevi with benign imaging characteristics and the potential to quantify horizontal growth using optical coherence tomography (OCT), in the absence of color fundus photography.

PURPOSE

This study aimed to present reports of two patients with pigmented choroidal tumors with low malignant potential based on their multimodal imaging features at the time of referral, but access to prior OCT imaging confirmed horizontal growth consistent with melanoma.Case ReportsTwo patients with pigmented, dome shaped, subfoveal tumors were referred. Both tumors had basal diameters greater than 5 mm, but no other risk factor for growth at the time of referral. Screening OCT scans had been taken of each patient's macula more than 5 years prior to referral, but color fundus photography was not available for either. Repeat OCT scanning at the time of referral showed horizontal growth of the tumors consistent with melanoma. As per the TFSOM-DIM ('To Find Small Ocular Melanoma - Do Imaging') risk factors assessment, the 5-year risk of growth of both tumors would be estimated at 11% at the time of referral, and, in the absence of the documented horizontal growth on OCT scanning, the patients would have been monitored for growth. After discussion of the risks and benefits, both patients elected for their tumors be managed as choroidal melanomas and underwent ruthenium plaque brachytherapy.

CONCLUSIONS

Horizontal growth of choroidal tumors can be established using sequential OCT scans in the absence of color fundus photography. Access to prior imaging can expedite the diagnosis of choroidal melanoma, potentially allowing patients to be treated earlier.

Identification of heterogeneity and prognostic key genes associated with uveal melanoma using single-cell RNA-sequencing technology

Uveal melanoma (UM) is the most common intraocular malignancy in adults. The prognosis is poor once metastasis has developed. The treatment of metastatic UM remains challenging nowadays due to lacking a deep understanding of the biological characteristics of this disease. Here, we revealed the cell subpopulations with distinct functional status and the existence of cells with high invasive potential within heterogeneous primary and metastatic UM. The single-cell sequencing data were retrieved from GSE139829 and GSE138433, through which we identified a new cell cluster related to metastatic UM as a unique type of immune cell. The cell-cell communication was conducted by 'Cellchat' to understand the cell crosstalk between these immune cells and their surrounding cells. The crucial signals contributing most to outgoing or incoming signaling of this cell group were identified to reveal the crucial pathway genes. Furthermore, we judged the prognostic value of these candidates on the basis of the data downloaded from The Cancer Genome Atlas. The results demonstrated that the increased IL10, SELPLG, EPHB and ITGB2 signaling pathways could be promising predicting factors for the patient prognosis in UM. Conclusively, we discover the potential key signals of UM for occurrence and metastasis, and also provide a theoretical basis for judging whether there is a high risk of metastasis or recurrence.

Histopathologic and MR Imaging Appearance of Spontaneous and Radiation-Induced Necrosis in Uveal Melanomas: Initial Results

Simple Summary

Uveal melanomas may undergo necrosis, both spontaneously or following radiotherapy. Nowadays radiotherapy is the preferred treatment, whereas enucleation of the eye is used in selected cases. In order to differentiate the effects of radiotherapy from spontaneous degenerative changes in uveal melanomas, we compared the appearance of necrosis, both from a histopathological point of view and from the perspective of MR imaging, in two groups of patients with uveal melanoma: a group who had undergone previous proton beam radiotherapy (secondary enucleation); a control group who had undergone enucleation without any previous radiotherapy treatment (primary enucleation). Irradiated and nonirradiated uveal melanomas differ on the basis of the histological appearance, the MR imaging appearance and the distribution of necrosis. We hope that the findings we observed could be extended to all patients with uveal melanomas treated with radiotherapy, and may enhance the accuracy of radiologists in evaluating MR examinations after radiotherapy.

Abstract

Necrosis in uveal melanomas can be spontaneous or induced by radiotherapy. The purpose of our study was to compare the histopathologic and MRI findings of radiation-induced necrosis of a group of proton beam-irradiated uveal melanomas with those of spontaneous necrosis of a control group of patients undergoing primary enucleation. 11 uveal melanomas who had undergone proton beam radiotherapy, MRI and secondary enucleation, and a control group of 15 untreated uveal melanomas who had undergone MRI and primary enucleation were retrospectively identified. Within the irradiated and nonirradiated group, 7 and 6 eyes with histological evidence of necrosis respectively, were furtherly selected for the final analysis; the appearance of necrosis was assessed at histopathologic examination and MRI. Irradiated melanomas showed a higher degree of necrosis as compared with nonirradiated tumors. Irradiated and nonirradiated lesions differed based on the appearance and distribution of necrosis. Irradiated tumors showed large necrotic foci, sharply demarcated from the viable neoplastic tissue; nonirradiated tumors demonstrated small, distinct foci of necrosis. Radiation-induced necrosis, more pigmented than surrounding viable tumor, displayed high signal intensity on T1-weighted and low signal intensity on T2-weighted images. The hemorrhagic/coagulative necrosis, more prevalent in nonirradiated tumors (4 out of 6 vs. 1 out of 7 cases), appeared hyperintense on T2-weighted and hypointense on T1-weighted images. Our study boosts the capability to recognize radiation-induced alterations in uveal melanomas at MRI and may improve the accuracy of radiologists in the evaluation of follow-up MR examination after radiotherapy.

Biopsy for molecular risk stratification in uveal melanoma: Yields and molecular characteristics in 119 patients

BACKGROUND

Prognostic cytological and molecular features of uveal melanoma have been well researched and are essential in management. Samples can be obtained in vivo through fine needle aspirate biopsy, vitrector cutter, forceps or post-enucleation for off-site testing. This study aims to examine cytological and chromosome microarray yields of these samples.

METHODS

A retrospective cohort analysis of 119 uveal melanoma biopsies submitted to our laboratory. Samples included those taken in vivo (n = 57) and post-enucleation (n = 62). Patient and tumour features were collected including age, sex, primary tumour location, basal diameter and tumour height. Prognostic outcomes measured include cell morphology, chromosomal status and immunohistochemistry.

RESULTS

Post-enucleation biopsies accounted for just over half of our samples (52%). Post-enucleation samples had a more successful genetic yield than in vivo biopsies (77% vs. 50%, p = 0.04) though there was no difference for cytological yields. There was no difference in cytological or microarray yields between instruments. The vitrector biopsy group had the smallest tumour thickness (5 mm vs. 10 mm [fine-needle aspirate biopsy], p = 0.003). There was a strong correlation between monosomy 3, BAP1 aberrancy and epithelioid cell type in post-enucleation samples (Tb  = 0.742, p = 0.005). However, epithelioid morphology was not associated with either monosomy 3 (p = 0.07) or BAP1 aberrancy (p = 0.24) for in vivo biopsies.

CONCLUSIONS

All three biopsy instruments provide similar cytological yields as post-enucleation sampling, although post-enucleation samples had a more successful chromosome microarray yield. Epithelioid cytomorphology alone is insufficient for prognostication in in vivo biopsies, immunohistochemistry would be a useful surrogate test.

Vitrectomy-Assisted Biopsy: An in vitro Study on the Impact of Cut Rate and Probe Size

Purpose

The aim of this study was to optimize the technique of performing vitrectomy-assisted biopsy of intraocular tumors by comparing the cytohistological findings in specimens obtained with different vitrectomy probes and cut rates.

Methods

Vitrectomy-assisted biopsies were taken from a fresh porcine liver. For each sampling, the vacuum level was 300 mm Hg. The following parameters were compared; cut rate (60, 600 and 6,000 cuts per minute [cpm]), probe type (standard and two-dimensional cutting [TDC]), and probe diameter (23-gauge and 25-gauge). The specimens were assessed by automated whole-slide imaging analysis and conventional light microscopy.

Results

Seventy-two biopsies were analyzed for the number of hepatocytes, total area of tissue fragments, and total stained area of each microscope slide. For all probe types, these parameters were significantly and positively correlated with the cut rate. TDC probes led to significantly higher scores than those of standard probes, independent of the cut rate. There were no significant differences in results when using 23-gauge or 25-gauge standard probes. Light microscopic examination demonstrated well-preserved cells sufficient for cytohistological analyses in all investigated cases.

Conclusions

The higher the cut rate, the larger is the amount of aspirated cellular material. There were no significant differences between 23-gauge and 25-gauge biopsies. Cut rates up to 6,000 cpm did not adversely affect the cytohistological features of the samples.

Intraocular fluid biomarkers (liquid biopsy) in human diabetic retinopathy

Purpose

This article aims to review the impact of detecting and quantifying intraocular biomarkers (liquid biopsy) in both aqueous and vitreous humor in eyes of people affected by diabetes mellitus.

Methods

This is a detailed review about aqueous and/or vitreous humor sampling in human diabetic eyes for proteomic and/or metabolomic analysis contributing to the understanding of the pathophysiology and treatment effects of diabetic retinopathy.

Results

Aqueous and vitreous humor molecular biomarkers proved to be directly correlated to each other and valuable to study retinal conditions. Moreover, proteomic and metabolomic analysis showed that the biomarkers of neuroinflammation, neurodegeneration, and vasculopathy are detectable in intraocular fluids and that their concentration changes in different stages of disease, and in response to treatment of all diabetic retinopathy aspects, mainly diabetic macular edema and proliferative retinopathy.

Conclusions

Liquid biopsy offers the possibility to improve our knowledge of intraocular eye disease induced by diabetes mellitus. The exact quantification of intraocular biomarkers contributes to the precision medicine approach even in the diabetic retinopathy scenario. The diffusion of this approach should be encouraged to have quantifiable information directly from the human model, which may be coupled with imaging data.

Circulating tumor DNA tracking through driver mutations as a liquid biopsy-based biomarker for uveal melanoma

BACKGROUND

Uveal melanoma (UM) is the most common intraocular tumor in adults. Despite good primary tumor control, up to 50% of patients develop metastasis, which is lethal. UM often presents asymptomatically and is usually diagnosed by clinical examination and imaging, making it one of the few cancer types diagnosed without a biopsy. Hence, alternative diagnostic tools are needed. Circulating tumor DNA (ctDNA) has shown potential as a liquid biopsy target for cancer screening and monitoring. The aim of this study was to evaluate the feasibility and clinical utility of ctDNA detection in UM using specific UM gene mutations.

METHODS

We used the highly sensitive digital droplet PCR (ddPCR) assay to quantify UM driver mutations (GNAQ, GNA11, PLCβ4 and CYSTLR2) in cell-free DNA (cfDNA). cfDNA was analyzed in six well established human UM cell lines with known mutational status. cfDNA was analyzed in the blood and aqueous humor of an UM rabbit model and in the blood of patients. Rabbits were inoculated with human UM cells into the suprachoroidal space, and mutated ctDNA was quantified from longitudinal peripheral blood and aqueous humor draws. Blood clinical specimens were obtained from primary UM patients (n = 14), patients presenting with choroidal nevi (n = 16) and healthy individuals (n = 15).

RESULTS

The in vitro model validated the specificity and accuracy of ddPCR to detect mutated cfDNA from UM cell supernatant. In the rabbit model, plasma and aqueous humor levels of ctDNA correlated with tumor growth. Notably, the detection of ctDNA preceded clinical detection of the intraocular tumor. In human specimens, while we did not detect any trace of ctDNA in healthy controls, we detected ctDNA in all UM patients. We observed that UM patients had significantly higher levels of ctDNA than patients with nevi, with a strong correlation between ctDNA levels and malignancy. Noteworthy, in patients with nevi, the levels of ctDNA highly correlated with the presence of clinical risk factors.

CONCLUSIONS

We report, for the first time, compelling evidence from in vitro assays, and in vivo animal model and clinical specimens for the potential of mutated ctDNA as a biomarker of UM progression. These findings pave the way towards the implementation of a liquid biopsy to detect and monitor UM tumors.

Current molecular and clinical insights into uveal melanoma (Review)

Uveal melanoma (UM) represents the most prominent primary eye cancer in adults. With an incidence of approximately 5 cases per million individuals annually in the United States, UM could be considered a relatively rare cancer. The 90-95% of UM cases arise from the choroid. Diagnosis is based mainly on a clinical examination and ancillary tests, with ocular ultrasonography being of greatest value. Differential diagnosis can prove challenging in the case of indeterminate choroidal lesions and, sometimes, monitoring for documented growth may be the proper approach. Fine needle aspiration biopsy tends to be performed with a prognostic purpose, often in combination with radiotherapy. Gene expression profiling has allowed for the grading of UMs into two classes, which feature different metastatic risks. Patients with UM require a specialized multidisciplinary management. Primary tumor treatment can be either enucleation or globe preserving. Usually, enucleation is reserved for larger tumors, while radiotherapy is preferred for small/medium melanomas. The prognosis is unfavorable due to the high mortality rate and high tendency to metastasize. Following the development of metastatic disease, the mortality rate increases to 80% within one year, due to both the absence of an effective treatment and the aggressiveness of the condition. Novel molecular studies have allowed for a better understanding of the genetic and epigenetic mechanisms involved in UM biological activity, which differs compared to skin melanomas. The most commonly mutated genes are GNAQ, GNA11 and BAP1. Research in this field could help to identify effective diagnostic and prognostic biomarkers, as well as novel therapeutic targets.

Intratumoral Heterogeneity in Uveal Melanoma

Tumor biopsies in uveal melanoma (UM) serve mainly the purpose of prognostication and assessment of individual metastatic risk, but can be used for diagnosis in selected cases. The importance of precise information is paramount for selecting adequate surveillance protocols, patient counseling, and optimization of treatment strategies. However, intratumoral heterogeneity and sample representativity are major concerns and can interfere with the correct prediction of the patient's prognosis. We report a series of cases of UM with distinct morphologically identifiable areas, highlighting the differences in clinical behavior, as well as histopathological and genetic features.

Instrument Gauge and Type in Uveal Melanoma Fine Needle Biopsy: Implications for Diagnostic Yield and Molecular Prognostication

PURPOSE

To systematically evaluate and compare the effects of using small-gauge needles and vitrectors on the ability to obtain adequate diagnostic and prognostic uveal melanoma biopsy specimens.

DESIGN

Comparative evaluation of biopsy instruments.

METHODS

Survival of uveal melanoma cells was evaluated in vitro following needle aspiration. Five therapeutically enucleated eyes were sampled in triplicate for ex vivo diagnostic biopsy experiments with 25 gauge (25 G) needle, 27 gauge (27 G) needle, and 27 G vitrector. During surgery in 8 patients, paired diagnostic transscleral fine needle aspiration biopsies were performed using both 25 G and 27 G needles. A review of cytologic specimens was performed by a panel of 3 expert cytopathologists. A retrospective chart review was performed to evaluate 100 consecutive tumors undergoing prognostic biopsy for gene expression profiling to assess the relationship between needle gauge and prognostic adequacy.

RESULTS

No significant cell shearing of uveal melanoma cells occurred in vitro with 25 G, 27 G, or 30 G needles. For ex vivo biopsy samples, diagnostic yield was 100% using 25 G needle (5/5) or 27 G vitrector (5/5) but 60% using a 27 G needle (3/5). For in vivo samples, no difference in diagnostic yield was found between 25 G (75%, 6/8) or 27 G (75%, 6/8) needle sizes. Of 100 molecular prognostic biopsy samples evaluated, 65 were obtained using 27 G needles; for these biopsies, the prognostic yield was 65/65 (100%).

CONCLUSIONS

For diagnostic biopsy of uveal melanoma, a larger-gauge needle or a 27 G vitrector may have better overall cellularity and diagnostic yield when compared to a 27 G needle. However, for much more common molecular prognostic testing, a 27 G needle provided adequate sample in 100% (65/65) of cases, and a larger needle provided no additional benefit.

Update on uveal melanoma: Translational research from biology to clinical practice (Review)

Uveal melanoma is the most common type of intraocular cancer with a low mean annual incidence of 5‑10 cases per million. Tumours are located in the choroid (90%), ciliary body (6%) or iris (4%) and of 85% are primary tumours. As in cutaneous melanoma, tumours arise in melanocytes; however, the characteristics of uveal melanoma differ, accounting for 3‑5% of melanocytic cancers. Among the numerous risk factors are age, sex, genetic and phenotypic predisposition, the work environment and dermatological conditions. Management is usually multidisciplinary, including several specialists such as ophthalmologists, oncologists and maxillofacial surgeons, who participate in the diagnosis, treatment and complex follow‑up of these patients, without excluding the management of the immense emotional burden. Clinically, uveal melanoma generates symptoms that depend as much on the affected ocular globe site as on the tumour size. The anatomopathological study of uveal melanoma has recently benefited from developments in molecular biology. In effect, disease classification or staging according to molecular profile is proving useful for the assessment of this type of tumour. Further, the improved knowledge of tumour biology is giving rise to a more targeted approach to diagnosis, prognosis and treatment development; for example, epigenetics driven by microRNAs as a target for disease control. In the present study, the main epidemiological, clinical, physiopathological and molecular features of this disease are reviewed, and the associations among all these factors are discussed.

UVEAL MELANOMA BIOPSY A REVIEW

In intraocular tumors, diagnosis is usually based on clinical examination and imaging without the need for invasive surgery or tissue sampling. The diagnosis can be confirmed by biopsy, however, in the case of intraocular malignancy, the biopsy is considered controversial. Due to the development of uveal melanoma cytogenetic prognostics and the progression in generalised uveal melanoma treatment, intraocular melanoma biopsy is becoming increasingly important. Diagnostic biopsy of intraocular tumors is indicated in cases of diagnostic uncertainty for findings with conflicting non-invasive test results and for small melanocyte lesions. Tumor prognostic biopsy is performed to obtain a tissue sample for tumor cytogenetic testing, which can help to determine the prognosis and specific metastatic risk of the patient. For anterior segment tumors, anterior chamber fluid sampling, thin-needle iris biopsy, punch biopsy, surgical biopsy or biopsy using vitrectomy may be used. For posterior segment tumors, procedures include transscleral or transretinal thin-needle biopsy, vitrectomy-assisted biopsy, punch biopsy, endoresection or transscleral exoresection. Complications of intraocular melanoma biopsy include too small or non-valuable sample collection, intra-tumoral heterogeneity, intra-ocular trauma and induction of intraocular or extraocular tumor dissemination.

Therapy of uveal melanoma A Review

The aim of intraocular melanoma therapy is to achieve local tumor control, reduce the risk of metastasis development, preserve the eyeball and possibly the visual function of the eye. The choice of therapeutic approach requires a comprehensive view and individual approach to each patient with uveal melanoma. Factors considered include local finding (location, tumor size and shape, tumor activity, central visual acuity, intraocular complications), age and the patients overall physical and psychological condition, as well as the patients wishes. The most widely used method of uveal melanoma treatment is radiotherapy. The effect of radiation is caused by the absorption of ionizing radiation energy, the effect of radiation on the cell is manifested by cell death (depletion), or by a cytogenetic information change (mutation). Brachytherapy uses scleral applicators with radionuclide - ruthenium (Ru-106) applicators dominate in Europe and iodine (I-125) applicators in the USA. In external radiotherapy, the source of ionizing radiation is outside the patients body. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy are used. In the Czech Republic, treatment is carried out using Leksell gamma knife or CyberKnife, while proton therapy dominates in the world. The development of serious radiation complications (radiation retinopathy, neuropathy, neovascular glaucoma, toxic tumor syndrome, etc.) should be considered. Surgical therapy involves a variety of invasive procedures. Iridectomy is performed for iris melanoma. Anteriorly located choroidal melanomas and / or ciliary body melanomas can be resolved by transscleral resection (exoresection). For posterior choroidal melanomas, a combination of external tumor irradiation with pars plana vitrectomy is used. Enucleation is a method of choice in advanced tumors that cannot be effectively irradiated. Orbital exenteration is indicated in advanced tumors with extrabulbar spread or in relapsed tumor after previous enucleation.

Molecular Genetics of Intraocular Tumors

PURPOSE

To explore the value of molecular technologies in the pathologic evaluation, diagnosis, and treatment of retinoblastoma and uveal melanoma.

METHODS

Review of the peer-reviewed literature on the molecular pathology of primary intraocular tumors.

CONCLUSION

Molecular tests are playing an increasingly important role in the diagnosis of intraocular tumors. They provide information valuable for diagnosis, prognosis, screening regimens, genetic counselling, and treatment. These technologies are becoming easier, faster, and with higher sensitivity and accuracy.