Prognostic Significance of Tumor-Associated Lymphangiogenesis in Malignant Melanomas of the Conjunctiva

The novel role of lymphatic vessels in the pathogenesis of ocular diseases

Historically, the eye has been considered as an organ free of lymphatic vessels. In recent years, however, it became evident, that lymphatic vessels or lymphatic-like vessels contribute to several ocular pathologies at various peri- and intraocular locations. The aim of this review is to outline the pathogenetic role of ocular lymphatics, the respective molecular mechanisms and to discuss current and future therapeutic options based thereon. We will give an overview on the vascular anatomy of the healthy ocular surface and the molecular mechanisms contributing to corneal (lymph)angiogenic privilege. In addition, we present (i) current insights into the cellular and molecular mechanisms occurring during pathological neovascularization of the cornea triggered e.g. by inflammation or trauma, (ii) the role of lymphatic vessels in different ocular surface pathologies such as dry eye disease, corneal graft rejection, ocular graft versus host disease, allergy, and pterygium, (iii) the involvement of lymphatic vessels in ocular tumors and metastasis, and (iv) the novel role of the lymphatic-like structure of Schlemm's canal in glaucoma. Identification of the underlying molecular mechanisms and of novel modulators of lymphangiogenesis will contribute to the development of new therapeutic targets for the treatment of ocular diseases associated with pathological lymphangiogenesis in the future. The preclinical data presented here outline novel therapeutic concepts for promoting transplant survival, inhibiting metastasis of ocular tumors, reducing inflammation of the ocular surface, and treating glaucoma. Initial data from clinical trials suggest first success of novel treatment strategies to promote transplant survival based on pretransplant corneal lymphangioregression.

Local Adenoviral Delivery of Vascular Endothelial Growth Factor C Induces Lymphangiogenesis in the Conjunctiva in Rabbits

INTRODUCTION

The purpose of this study was to determine if conjunctival lymphangiogenesis can be induced using adenoviral delivery of vascular endothelial growth factor C (VEGF-C).

METHODS

Seventeen New Zealand white rabbits received a subconjunctival injection containing 3.5 × 107 plaque-forming units of an adenoviral vector containing the gene-encoding VEGF-C (Ad-VEGF-C). The contralateral eye was used for control experiment (the same volume of either saline or an empty vector). After 2 weeks, the animals were examined with trypan blue conjunctival lymphangiography, and the eyes were harvested for histology and immunohistochemistry (podoplanin and CD31).

RESULTS

Trypan blue conjunctival lymphangiography revealed significantly more extensive conjunctival vessel network in the Ad-VEGF-C group compared with control: 1.35 ± 0.67 versus 0.28 ± 0.17 vessel length/analysed area (p = <0.0001). This finding was confirmed with immunohistochemistry, where a significant increase in the number of lymphatic vessels was found compared to control; 34 ± 9 per mm2 versus 13 ± 8 per mm2 (p = 0.0019). Furthermore, there was a significant increase in lymphatic cross-sectional area; 32,500 ± 7,900 µm2 per mm2 versus 17,600 ± 9,700 µm2 per mm2 (p = 0.0149). Quantification of blood vessels revealed no significant difference in blood vessel density between Ad-VEGF-C and control; 19 ± 9 per mm2 versus 14 ± 8 per mm2 (p = 0.1971). There was no significant difference in total blood vessel area; 13,200 ± 7,600 µm2 per mm2 versus 7,100 ± 3,000 µm2 per mm2 (p = 0.0715). Eyes treated with an adenoviral vector (VEGF-C or empty vector) responded with a reactive cellular response, predominantly lymphocytes, towards the vector.

CONCLUSION

The study demonstrates the feasibility of inducing conjunctival lymphangiogenesis with a single subconjunctival injection of Ad-VEGF-C. Future studies will explore how this can be used with a therapeutic purpose.

Bindehautdegenerationen und -neoplasien

Erhabenheiten der Bindehaut entstehen durch Gewebevermehrung, die entweder degenerativ oder neoplastisch, aber auch entzündlich sein können. In diesem Artikel werden degenerative (Pterygium und Pinguecula) sowie benigne und maligne neoplastische Bindehautveränderungen (epitheliale, melanozytäre und vaskuläre Tumoren, Choristome sowie Metastasen) bezüglich der Pathogenese, Symptome, Diagnostik und aktuellem Stand der Behandlung dargestellt.

[Conjunctival Degeneration and Neoplasia]

Conjunctival tumors result from gain of tissue, which can be either degenerative or neoplastic, but also inflammatory. In this article, degenerative (pterygium and pinguecula) as well as benign and malignant neoplastic conjunctival changes (epithelial, melanocytic and vascular tumors, choristomas as well as metastases) are discussed with regard to pathogenesis, symptoms, diagnostics and current status of treatment.

New Therapeutic Approaches for Conjunctival Melanoma-What We Know So Far and Where Therapy Is Potentially Heading: Focus on Lymphatic Vessels and Dendritic Cells

Conjunctival melanoma (CM) accounts for 5% of all ocular melanomas and arises from malignantly transformed melanocytes in the conjunctival epithelium. Current therapies using surgical excision in combination with chemo- or cryotherapy still have high rates for recurrences and metastatic disease. Lately, novel signal transduction-targeted and immune checkpoint inhibitors like cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, programmed cell death protein-1 (PD-1) receptor inhibitors, BRAF- or MEK-inhibitors for systemic treatment of melanoma have improved the outcome even for unresectable cutaneous melanoma, improving patient survival dramatically. The use of these therapies is now also recommended for CM; however, the immunological background of CM is barely known, underlining the need for research to better understand the immunological basics when treating CM patients with immunomodulatory therapies. Immune checkpoint inhibitors activate tumor defense by interrupting inhibitory interactions between tumor cells and T lymphocytes at the so-called checkpoints. The tumor cells exploit these inhibitory targets on T-cells that are usually used by dendritic cells (DCs). DCs are antigen-presenting cells at the forefront of immune response induction. They contribute to immune tolerance and immune defense but in the case of tumor development, immune tolerance is often prevalent. Enhancing the immune response via DCs, interfering with the lymphatic pathways during immune cell migration and tumor development and specifically targeting tumor cells is a major therapeutic opportunity for many tumor entities including CM. This review summarizes the current knowledge on the function of lymphatic vessels in tumor growth and immune cell transport and continues to compare DC subsets in CM with related melanomas, such as cutaneous melanoma and mucosal melanoma.

The prognostic influence of lymphatic endothelium-specific hyaluronan receptor 1 in cancer: A systematic review

Lymphangiogenesis is a key process in cancer development and metastasis. Lymphatic vessel endothelial hyaluronan receptor 1 (LYVE‐1) is a widely used marker for lymphatic endothelial cells (LEC), which also mediates immune and cancer cell migration. Recently, LYVE‐1–positive tumor cells were shown to acquire LEC‐like phenotype and exploit this receptor for lymphatic dissemination. Furthermore, selective targeting of LYVE‐1 impaired the growth of cancer‐related vasculature and reduced metastasis in vivo, signifying its role in therapeutic and prognostic applications. Although numerous studies have investigated the role of LYVE‐1 in cancer, a unifying detailed review of its prognostic utility is lacking to date. Thus, we compiled and critically appraised evidence from clinical studies comprising a total of 2352 patients diagnosed with different types of cancer and using a variety of experimental approaches. Collectively, most studies revealed a significant association between LYVE‐1 overexpression and dismal outcome of at least one survival estimate. Furthermore, the importance of vasculature location, intra‐ or peritumoral, and the influence of various lymphangiogenesis‐related parameters, such as lymphatic vessel density and invasion, were discussed. However, the specificity of LYVE‐1 staining is challenged by its expression in non‐LEC cells, implying the need for double labelling to better estimate its prognostic significance. In conclusion, this is to our knowledge the first comprehensive systematic review on the prognostic value of LYVE‐1 in cancer. More well‐designed studies across different populations and the development of standardized protocols would be paramount for the consistency of LYVE‐1 findings and for its potential transferability to clinical practice in future.

Anterior Segment OCTA of Melanocytic Lesions of the Conjunctiva and Iris

PURPOSE

To study the feasibility and diagnostic value of vascular imaging using optical coherence tomography (OCT)-angiography (OCTA) of melanocytic lesions of the conjunctiva and iris.

DESIGN

Cross-sectional study.

METHODS

Twenty-five patients with an untreated conjunctival lesion (5 melanoma, 13 nevus, 7 primary acquired melanosis [PAM]) and 52 patients with an untreated iris lesion (10 melanoma, 42 nevus) were included. Patients were imaged using a commercially available OCTA device, with the addition of an anterior segment lens and manual focussing. Tumor vessel presence, vascular patterns and vascular density were assessed.

RESULTS

Good OCTA images were obtained in 18 of 25 conjunctival lesions and 42 of 52 iris lesions. Failure was caused by lack of patient cooperation, an unfavorable location, or mydriasis. In all imaged conjunctival lesions and 77% of iris lesions, vascular structures were detected. Conjunctival melanoma and nevi demonstrated the same intralesional tortuous patterns, whereas vasculature in eyes with PAM was similar to normal conjunctiva. Both iris melanoma and nevi demonstrated tortuous patterns, distinct from the radially oriented normal iris vasculature.

CONCLUSIONS

Optical coherence tomography angiography (OCTA) allows for noninvasive imaging of the vasculature in melanocytic lesions of the conjunctiva and iris. Good image quality depends highly on patient cooperation and lesion characteristics. Differentiation of benign and malignant lesions was not possible. New software is called for to improve image acquisition and analysis.

Genetics of Ocular Melanoma: Insights into Genetics, Inheritance and Testing

Ocular melanoma consists of posterior uveal melanoma, iris melanoma and conjunctival melanoma. These malignancies derive from melanocytes in the uveal tract or conjunctiva. The genetic profiles of these different entities differ from each other. In uveal melanoma, GNAQ and GNA11 gene mutations are frequently found and prognosis is based on mutation status of BAP1, SF3B1 and EIF1AX genes. Iris melanoma, also originating from the uvea, has similarities to the genetic makeups of both posterior uveal melanoma (UM) and conjunctival melanoma since mutations in GNAQ and GNA11 are less common and genes involved in conjunctival melanoma such as BRAF have been described. The genetic spectrum of conjunctival melanoma, however, includes frequent mutations in the BRAF, NRAS and TERT promoter genes, which are found in cutaneous melanoma as well. The BRAF status of the tumor is not correlated to prognosis, whereas the TERT promoter gene mutations are. Clinical presentation, histopathological characteristics and copy number alterations are associated with survival in ocular melanoma. Tissue material is needed to classify ocular melanoma in the different subgroups, which creates a need for the use of noninvasive techniques to prognosticate patients who underwent eye preserving treatment.

Interdisciplinary Surveillance of Ocular Melanomas: Experiences in a German Tertiary Centre

BACKGROUND

In contrast to cutaneous melanoma, there are no uniform guidelines regarding surveillance of ocular (uveal, conjunctival) melanomas. A consented standard operating procedure (SOP) by the "Netzwerk onkologische Spitzenzentren" Germany only exists for conjunctival melanoma but not for uveal melanoma. Surveillance is partially based on German S3-guidelines for cutaneous melanoma and is carried out by oncologic centres in a multidisciplinary approach. This study aims to evaluate patients' adherence to surveillance programs and whether surveillance recommendations (examinations, intervals) can be realised.

METHODS

Retrospective analysis of all ocular melanoma patients overseen at the University Hospital of Cologne between 2008 and 2019. The study evaluates rates of successful patient integration into a standardized surveillance program and patients' surveillance adherence, subject to age, gender, primary therapy and tumour entity, respectively.

RESULTS

99 patients were included (56 female, 43 male), 83 of which had uveal melanomas and 16 conjunctival melanomas. Mean follow-up was 59 months. 81% of patients were integrated into a surveillance program. Surveillance was performed according to published recommendations in 78%. 13% of patients dropped out of the surveillance program after a mean period of 38 months.

CONCLUSIONS

Our data show a growing number of patients in standardized surveillance. However, there are still gaps. There is a need for guidelines specifically designed for ocular melanomas, allowing centres to offer patients an individualized approach.

Conjunctival Melanoma with Ipsilateral, Non-Contiguous Eyelid Involvement: A Case Report and Comprehensive Review of the Literature

While the majority of cases of conjunctival melanoma (CM) involve the bulbar conjunctiva, concurrent pigmentation of the ipsilateral eyelid can be seen in up to 15% of cases. Although extension of conjunctival melanoma into the eyelid (AJCC cT3b) occurs in 1% of cases, non-contiguous lesions are very rare with only 5 clearly documented reports in the English literature. Several pathophysiological mechanisms have been proposed, including separate primary melanomas, patchy involvement from primary acquired melanosis (which may be sine pigmento) and exfoliation of malignant tumour cells into the tear film. Herein we present a case of eyelid melanoma arising in a patient previously treated for CM at a non-contiguous site and provide a comprehensive review of the relevant literature.

Clinical treatment options for early-stage and advanced conjunctival melanoma

Conjunctival melanoma (CM) is an ocular malignant tumor arising from the bulbar and palpebral conjunctiva and from the caruncle. The treatment of early-stage CM is wide local excision, followed by cryotherapy to the margins and adjuvant therapy postoperatively. Advanced CM has a poor prognosis, and there is no consensus on its management. With the development of precision medicine, the identification of genetic alterations assumes great importance. The genetic characteristics of CM, such as BRAF, NRAS, and NF1 mutations, may provide potential therapeutic targets. For locally advanced tumors and metastatic disease, targeted therapy such as BRAF inhibitors and MEK inhibitors in vitro show therapeutic benefit. Some individual case reports indicate their potential effectiveness in advanced CM. In addition, immune checkpoint inhibitors, such as programmed cell death-1 and cytotoxic T lymphocyte antigen-4 inhibitors, have been successfully used for advanced cutaneous melanoma and may be effective in CM. Limited clinical case reports found immune checkpoint inhibitors effective in advanced CM. More clinical studies are needed.

[Personalized medicine in the treatment of periocular tumors : Targeted treatment and use of immune checkpoint inhibitors]

The aim of this article is to provide an overview on the current state of personalized medicine in the systemic treatment of selected periocular tumors, such as basal cell carcinoma, Merkel cell carcinoma and conjunctival melanoma. This article therefore provides an extensive current literature review from PubMed including the current guidelines and standard operating procedures (SOP). As 90% of basal cell carcinomas have a pathologic activation of the sonic hedgehog pathway, vismodegib is a new treatment option for inoperable or metastatic basal cell carcinoma and for patients with Gorlin-Goltz syndrome. A novel approach of systemic medicine for the treatment of metastatic Merkel cell carcinoma is immunotherapy using the immune checkpoint inhibitor avelumab. Other personalized immunotherapies, such as the checkpoint inhibitors pembrolizumab and nivolumab, the tyrosine kinase inhibitor pazopanib and the role of the hedgehog pathway in Merkel cell carcinomas are the subject of current research and will certainly play an important role in future treatment. In the narrow sense personalized medicine has only come true for metastatic conjunctival melanomas: systemic treatment with BRAF, MEK and/or checkpoint inhibitors is initiated only when a BRAF mutation is detected in the tumor or metastatic tissue. Systemic immunotherapy with the checkpoint inhibitors pembrolizumab and nivolumab can also be used as a treatment option in metastatic conjunctival melanomas. In summary, personalized medicine is a subject of current research and provides many new targeted treatment options especially for periocular malignancies; however, it also involves many great challenges in the development and implementation of new techniques and therapies.

Conjunctival Melanoma Angiotropic Microsatellitosis: A Mechanism of Local Extravascular Migratory Metastasis

Purpose

To report a case of local metastasis of conjunctival melanoma, which may occur via extravascular migratory metastasis (EVMM), and discuss its clinical relevance in conjunctival melanoma tumor staging and possible management implications.

Methods

Retrospective chart review of a single clinical case with clinicopathologic correlation.

Results

A 65-year-old male referred due to local recurrence of conjunctival melanoma at the caruncle was successfully treated after two excisional procedures with negative sentinel lymph node biopsies. Forty-eight months after initial presentation, the patient developed a nodular lesion representing local recurrence in the ipsilateral upper tarsal conjunctiva, distant from the primary tumor site. Histopathology showed nodules in the substantia propria in the absence of primary acquired melanosis. The tumor cells were found along the extravascular surface without intralymphatic or intravascular tumor cells consistent with local metastasis. One possible mechanism is angiotropic microsatellitosis leading to local EVMM. Additional neck CT imaging showed no lymphadenopathy.

Conclusion

EVMM via angiotropic microsatellitosis is another possible mechanism of noncontiguous local recurrence of conjunctival melanoma. Angiotropic microsatellitosis may represent a high-risk finding possibly related to increased melanoma-related mortality.

Sentinel lymph node biopsy in the management of conjunctival melanoma: current insights

Purpose: To evaluate the role of sentinel lymph node biopsy (SLNB) in conjunctival melanoma (CM).

Methods: This article provides a review of the literature from PUBMED.

Results: Data on SLNB in the management of CM are scarce and only two relatively large cohorts have been reported. Although indication criteria for SLNB vary slightly, positive findings can be expected in 11%–13% of CM cases, including small tumors. False negative SLNB findings are rare (<10%). Failure to identify SLNB has been attributed to the surgical learning curve and recurrent tumors with scar tissue impeding spread of the tracer material. Reported 5-year survival rate following CM management including SLNB, is up to 79%, but there are no comparative cohort studies proving the assumed benefit. Adverse events reported were non-severe and transient.

Conclusion: Patients can potentially benefit from SLNB and the procedure can be offered to eligible patients. However, there is not enough evidence to support SLNB as a mandatory part of CM management.

Expression of VEGF in human conjunctival melanoma analyzed with immunohistochemistry

Purpose

The aim of this study was to examine the immunolocalization of VEGF-A and CD34, a marker of endothelial cells, in human conjunctival melanoma.

Methods

This study retrospectively analyzed primary conjunctival melanoma patients who underwent surgical resection of the tumor. All excised tissues were fixed with paraformaldehyde and embedded in paraffin, which were then submitted for immunohistochemistry with anti-VEGF and CD34 antibodies.

Results

The study sample comprised 4 female and two male melanoma patients. The age of the patients ranged from 64 to 84 (average age, 73) years. Histopathology of the surgically resected tumor tissues demonstrated accumulation of polygonal atypical malignant cells producing melanin. Cytoplasmic immunoreactivity for VEGF was clearly observed in tumor cells of all six tumors. In contrast, CD34-positive endothelial cells were less marked in the melanoma tissues than in the adjacent noncancerous subconjunctival stroma.

Conclusion

VEGF immunoreactivity was observed in conjunctival melanoma tissues, in which endothelial cells were hardly observed. These results suggest that although VEGF is expressed, conjunctival melanoma is a hypovascular tumor.

Detection of Pro- and Antiangiogenic Factors in the Human Sclera

PURPOSE

Avascular tissues can be used to identify antilymph- or antihemangiogenic factors. The human sclera-the outer covering layer of the eye, lacks lymphatic vessels and contains only a superficial network of blood vessels and was used here to identify endogenous antiangiogenic factors.

METHODS

Expression levels of a panel of 96 known pro- and antiangiogenic factors were analyzed in 12 scleral or conjunctival control samples from normal human donors using real-time PCR. In vitro, scleral homogenate was cocultured with blood- and lymphatic endothelial cells (BECs and LECs) and immunohistochemistry was performed of scleral fibroblasts and BECs.

RESULTS

Three antiangiogenic factors were significantly upregulated in the human sclera compared to the conjunctiva, including FBLN5 (fibulin 5), SERPINF1 (serpin peptidase inhibitor, clade F, member 1 = pigment epithelium derived factor) and TIMP2 (Tissue inhibitor of metalloproteinases 2). Six proangiogenic factors were significantly downregulated in the sclera, including FLT4 (Fms-related tyrosine kinase 4=VEGF-R3), HGF (hepatocyte growth factor), KIT (CD117 / c-kit), PROX1 (prospero homeobox 1), SEMA3F (semaphorin-3F) and TGFA (transforming growth factor alpha). In vitro, scleral homogenate inhibited the growth of both BECs and LECs. Immunohistochemistry labeling of three major antiangiogenic factors from scleral tissue confirmed TIMP3 and PEDF expression both in scleral fibroblasts and in blood endothelial cells, whereas TIMP2 was not detectable.

CONCLUSION

Balancing anti- and proangiogenic factors actively regulates human scleral avascularity, inhibits endothelial cell growth in vitro, and thus may help maintaining the vascular privilege of the inner eye.

Vascular-Associated Muc4/Vwf Co-Localization in Human Conjunctival Malignant Melanoma Specimens-Tumor Metastasis by Migration?

PURPOSE

To investigate whether vascular differentiation marker von Willebrand factor (vWf) and proliferation marker KI67 expression correlate with MUC4 localization around stromal tumor vascularization in human conjunctival malignant melanoma (CMM).

MATERIALS AND METHODS

For the purposes of this study, we analyzed samples from human CMMs (n = 4), conjunctival compound nevi (n = 7), and samples from healthy conjunctiva (n = 7) for MUC1, 4, and 16 by immunohistochemistry. To test CMM vessel association of MUC4, we investigated the co-localization of MUC4 with vWf or KI67 in human CMM specimens (n = 10) by immunohistochemistry. Also, we investigated the MUC4 localization around vessels of healthy conjunctiva (n = 10).

RESULTS

The immunohistochemical analysis demonstrated membrane-associated mucin expression in epithelia of CMM, nevi and healthy conjunctiva, whereas only MUC4 was localized perivascular in CMM tissue in this preliminary analysis. Co-staining analysis with vWf and KI67 demonstrated MUC4 localization around stromal vessels in human CMM specimens. In contrast, no MUC4 localization has been seen around healthy conjunctiva stroma vessels.

CONCLUSIONS

MUC4 was detected around vWf/KI67-positive CMM stromal vascular tissue, but not around healthy conjunctival stroma vessels. Therefore, we assume that MUC4 might play a role in tumor cell migration toward vessels inducing metastasis.

Sentinel lymph node biopsy for ocular adnexal melanoma

BACKGROUND

We sought to update our prior report of findings on sentinel lymph node biopsy (SLNB) and predictors of a positive SLN in patients with conjunctival or eyelid melanoma.

METHODS

We reviewed the records of all patients with ocular adnexal melanoma who underwent SLNB at one institution during 2000-2015. We determined rates of positive and false-negative findings on SLNB, primary tumour features correlated with positive findings and rate of nodal recurrence (false-negative event) after negative findings.

RESULTS

The study included 51 patients, 31 with conjunctival and 20 with eyelid melanoma. These patients include 30 patients who underwent SLNB during 2000-2008, described in our previous report, and 21 additional patients who underwent SLNB during 2008-2015. There were 30 women and 21 men with median age at SLNB of 62 years (range, 24-83). The nodal basins most commonly sampled were intraparotid (27 patients) and level II (14 patients). Ten patients had positive SLNB findings. Compared to tumours with negative findings, tumours with positive findings had greater median thickness (3.5 mm versus 2.2 mm, p = 0.04), greater median number of mitotic figures (6 versus 2, p = 0.03) and greater incidence of ulceration (80% versus 26%, p = 0.003). Perineural and vascular invasion were not significantly associated with positive findings. There were three false-negative events. Three patients (6%) had temporary marginal mandibular weakness which resolved spontaneously.

CONCLUSION

SLNB in patients with ocular adnexal melanoma is safe and identifies nodal micrometastasis in approximately 20% of cases. Histologic features associated with a positive SLN included greater tumour thickness, greater number of mitotic figures and ulceration.

[Adjuvant therapy and interdisciplinary follow-up care of conjunctival melanoma]

BACKGROUND

Despite microscopically controlled tumor excision, malignant melanomas of the conjunctiva have a propensity for local recurrence, lymphatic spread and distant metastases.

OBJECTIVES

This review outlines the options of adjuvant therapy as well as the structure of interdisciplinary follow-up care for patients with conjunctival melanoma.

METHODS

The study provides a PubMed literature review and own clinical results.

RESULTS

In conjunctival melanoma complete tumor excision using a minimal touch technique should always be combined with adjuvant therapy, such as cryotherapy, radiotherapy, topical chemotherapy and/or immunotherapy. For locally circumscribed lesions of the bulbar conjunctiva adjuvant brachytherapy can be supplemented and for non-bulbar, extensive, diffuse or multilocular tumor growth, complementary adjuvant topical mitomycin C therapy or proton radiotherapy can be used. Novel adjuvant approaches include topical interferon alpha-2b immunotherapy, topical vascular endothelial growth factor (VEGF) inhibitors or in cases of BRAF mutations personalized therapy using selective BRAF inhibitors or in combination with mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK), MAPK/ERK (MEK) inhibitors. All patients should be integrated into an interdisciplinary follow-up care program including quarter yearly checkups in the first 5 years and psycho-oncological healthcare.

CONCLUSION

Following microscopically controlled tumor excision, adjuvant treatment using cryotherapy, radiotherapy, topical chemotherapy and/or immunotherapy as well as interdisciplinary follow-up care are mandatory for the modern management of patients with conjunctival melanoma.

Systemic BRAF/MEK Inhibitors as a Potential Treatment Option in Metastatic Conjunctival Melanoma

AIM

In this review, we outline similarities between conjunctival and skin melanoma as well as the effectiveness of combined BRAF/MEK inhibition in melanoma, and discuss the applicability of these agents in conjunctival melanoma.

METHODS

The study provides a PubMed literature review.

RESULTS

Conjunctival melanoma and skin melanoma are genetically and phenotypically related. Both tumors typically harbor BRAF mutations in more than 50% of cases. New targeted therapies in metastatic skin melanoma include selective inhibition of BRAF and MEK. Combined BRAF/MEK inhibition has revolutionized the treatment of metastatic skin melanoma, significantly improving patients' prognoses. While these new substances have been investigated extensively in the treatment of skin melanoma, comparable studies in conjunctival melanoma do not exist owing to the rarity of the malignancy.

CONCLUSIONS

The application of combined BRAF/MEK inhibition in metastatic or unresectable conjunctival melanoma shows great potential for improving patients' prognoses. Future studies are needed to investigate the assumed benefit.

Expression of Molecular Markers of Angiogenesis, Lymphangiogenesis, and Proliferation Depending on the Stage of Skin Melanoma

The expression of molecular markers characterizing activity of the tumor process and metastases (proliferation marker Ki-67, angiogenesis marker CD34, and lymphangiogenesis markers podoplanin and LYVE-1) was assessed by immunohictochemical method in the primary tumor specimens collected during surgery for cutaneous melanoma (40 patients). Proliferative activity of the tumor tissue and volume density of peritumoral blood and lymph vessels increased with increasing tumor malignancy, which could indicate the risk of metastases.

Advances in the management of conjunctival melanoma

Malignant melanoma of the conjunctiva is a rare but serious condition. Over the last several years, there have been important advances in the classification, diagnosis, and treatment of this condition. Recent cytogenetic and immunohistochemical studies are increasing understanding of its tumorigenesis. Diagnosis, although still made via histopathology, has been aided with imaging techniques such as ultrasound biomicroscopy and anterior segment optical coherence tomography. Primary treatment consists of surgical excision. But adjuvant treatments with cryotherapy, topical chemotherapy, and radiation therapy have shown increased success. Sentinel lymph node biopsy has shown early promise of detecting micro-metastasis. Long term follow-up of patients with conjunctival melanoma with systemic surveillance is necessary to detect recurrences and metastases.

Tumor lymphangiogenesis and new drug development

Traditionally, tumor-associated lymphatic vessels have been regarded as passive by-standers, serving simply as a drainage system for interstitial fluid generated within the tumor. However, with growing evidence that tumors actively induce lymphangiogenesis, and that the number of lymphatic vessels closely correlates with metastasis and clinical outcome in various types of cancer, this picture has changed dramatically in recent years. Tumor-associated lymphatic vessels have now emerged as a valid therapeutic target to control metastatic disease, and the first specific anti-lymphangiogenic drugs have recently entered clinical testing. Furthermore, we are just beginning to understand the whole functional spectrum of tumor-associated lymphatic vessels, which not only concerns transport of fluid and metastatic cells, but also includes the regulation of cancer stemness and specific inhibition of immune responses, opening new venues for therapeutic applications. Therefore, we predict that specific targeting of lymphatic vessels and their function will become an important tool for future cancer treatment.

Antilymphangiogenic therapy to promote transplant survival and to reduce cancer metastasis: what can we learn from the eye?

The lymphatic vasculature is - amongst other tasks - essentially involved in inflammation, (auto)immunity, graft rejection and cancer metastasis. The eye is mainly devoid of lymphatic vessels except for its adnexa, the conjunctiva and the limbus. However, several pathologic conditions can result in the secondary ingrowth of lymphatic vessels into physiologically alymphatic parts of the eye such as the cornea or the inner eye. Therefore, the cornea has served as an excellent in vivo model system to study lymphangiogenesis, and findings from such studies have substantially contributed to the understanding of central principles of lymphangiogenesis also with relevance outside the eye. Grafting experiments at the cornea have been extensively used to analyze the role of lymphangiogenesis in transplant immunology. In this regard, we recently demonstrated the crucial role of lymphatic vessels in mediating corneal allograft rejection and could show that antilymphangiogenic therapy increases graft survival. In the field of cancer research, we recently detected tumor-associated lymphangiogenesis in the most common malignant tumors of the eye, such as conjunctival carcinoma and melanoma, and ciliochoroidal melanoma with extraocular extension. These neolymphatics correlate with an increased risk of local recurrence, metastasis and tumor related death, and may offer potential therapeutic targets for the treatment of these tumors. This review will focus on corneal and tumor-associated ocular lymphangiogenesis. First, we will describe common experimentally used corneal lymphangiogenesis models and will recapitulate recent findings regarding the involvement of lymphatic vessels in corneal diseases and transplant immunology. The second part of this article will summarize findings about the participation of tumor-associated lymphangiogenesis in ocular malignancies and their implications for the development of future therapeutic strategies.

Impact of the prolymphangiogenic crosstalk in the tumor microenvironment on lymphatic cancer metastasis

Lymphangiogenesis is a very early step in lymphatic metastasis. It is regulated and promoted not only by the tumor cells themselves, but also by cells of the tumor microenvironment, including cancer associated fibroblasts, mesenchymal stem cells, dendritic cells, or macrophages. Even the extracellular matrix as well as cytokines and growth factors are involved in the process of lymphangiogenesis and metastasis. The cellular and noncellular components influence each other and can be influenced by the tumor cells. The knowledge about mechanisms behind lymphangiogenesis in the tumor microenvironmental crosstalk is growing and offers starting points for new therapeutic approaches.

Ocular melanoma

Ocular melanomas comprise uveal and conjunctival sub-types, which are very different from each other. A large majority of uveal melanomas involve the choroid, with less than 10% being confined to the ciliary body and iris. They tend to metastasize haematogenously, almost always involving the liver. Therapeutic methods include various forms of radiotherapy, surgical resection and phototherapy, which are often used in combination. Conjunctival melanomas show many similarities to their cutaneous counterparts, often metastasizing by lymphatic spread. Treatment consists of excision of invasive melanoma with adjunctive radiotherapy and/or cryotherapy and topical chemotherapy for intra-epithelial disease. The management of patients with ocular melanomas demands a good understanding of the pathology of these tumours. Pathological examination of the tumour indicates the prognosis and hence the need for further investigation and treatment. The scope of the pathologist is enhanced thanks to advances in molecular biology.

Conjunctival melanoma: a review of conceptual and treatment advances

The aim of this study was to review the available literature and identify recent advances in the classification and management of conjunctival melanoma (CM) for clinicians working in this field. English-based articles were identified using the MEDLINE^® database, and additional cited works not detected in the initial search were also obtained. Articles were assessed according to the Australian National Health and Medical Research Council levels of evidence criteria. Review of the literature indicated that the current classification and management of CM is predominantly based upon primarily nonrandomized, single-institution, retrospective case series. While these studies provide the basis for the recent seventh edition of the tumor node metastasis staging classification, this classification more accurately reflects the current knowledge of prognostic factors for CM. Application of this revised classification system together with prospective trials will provide the opportunity for future consistent and comparable data collection across centers, and it will improve the quality of evidence upon which current classification and management of CM is based. Furthermore, the high risk of local recurrence with current standard management suggests that adjuvant therapy, particularly mitomycin C and/or brachytherapy, may improve outcomes regardless of clinical staging. Finally, the use of sentinel lymph node biopsy may have significant benefit for a select group of CM patients.

Novel anti(lymph)angiogenic treatment strategies for corneal and ocular surface diseases

The cornea is one of the few tissues which actively maintain an avascular state, i.e. the absence of blood and lymphatic vessels (corneal [lymph]angiogenic privilege). Nonetheless do several diseases interfere with this privilege and cause pathologic corneal hem- and lymphangiogenesis. The ingrowths of pathologic blood and lymphatic vessels into the cornea not only reduce transparency and thereby visual acuity up to blindness, but also significantly increases the rate of graft rejections after subsequent corneal transplantation. Therefore great interest exists in new strategies to target pathologic corneal (lymph)angiogenesis to promote graft survival. This review gives an overview on the vascular anatomy of the normal ocular surface, on the molecular mechanisms contributing to the corneal (lymph)angiogenic privilege and on the cellular and molecular mechanisms occurring during pathological neovascularization of the cornea. In addition we summarize the current preclinical and clinical evidence for three novel treatment strategies against ocular surface diseases based on targeting pathologic (lymph)angiogenesis: (a) modulation of the immune responses after (corneal) transplantation by targeting pathologic (lymph)angiogenesis prior to and after transplantation, (b) novel concepts against metastasis and recurrence of ocular surface tumors such as malignant melanoma of the conjunctiva by anti(lymph)angiogenic therapy and (c) new ideas on how to target ocular surface inflammatory diseases such as dry eye by targeting conjunctival and corneal lymphatic vessels. Based on compelling preclinical evidence and early data from clinical trials the novel therapeutic concepts of promoting graft survival, inhibiting tumor metastasis and dampening ocular surface inflammation and dry eye disease by targeting (lymph)angiogenesis are on their way to translation into the clinic.

Management of pigmented conjunctival lesions

Pigmented conjunctival lesions primarily include melanoma, nevus, primary acquired melanosis (PAM), and complexion-associated melanosis. The incidence of conjunctival malignant melanoma (CMM) has significantly increased in the USA and Europe over the years, and it carries a very serious risk for metastasis and melanoma-related death. Conjunctival melanoma can arise de novo or from precursor lesions, nevus, and PAM. PAM is histologically separated into two distinct forms: PAM with atypia and without atypia. PAM with severe atypia progresses to malignant melanoma in up to 50% of cases and PAM without atypia virtually never progresses. Nevus is a benign melanocytic tumor that only rarely undergoes malignant transformation. Complexion-associated melanosis is frequently seen in more darkly pigmented individuals and does not progress to melanoma, although it can become very large. A detailed literature review on the various pigmented conjunctival lesions together with a schematic approach to diagnosis and management is presented.

When narrative medicine helps in the diagnosis of conjunctival melanoma - an exceptional case report

Introduction: Conjunctival melanoma is a relatively rare ocular malignancy with substantial associated morbidity and mortality. It can arise in previously unblemished and unpigmented regions (approximately 10% of cases), from a preexisting nevus (approximately 20% of cases), or from the flat, spreading pigmentation of primary acquired melanosis with atypia (60–70% of cases), actually called conjunctival melanocytic intraepithelial neoplasia (C-MIN) with atypia (histopathologically more accurately term).

Purpose: The authors describe an extremely rare case of malignant conjunctival melanoma, with a long evolution, in a young black woman.

Results: Until now the patient has not shown any sign of relapse of this melanoma, after local excision.

Conclusion: Conjunctival melanoma is a condition of concern because of its rarity and lethal potential. Advances in the understanding and management of this neoplasm have markedly reduced the mortality and possibly the morbidity associated with this malignancy. We observe that there are some cases of conjunctival melanoma that might be cured with only a local excision with posterior cryotherapy without more aggressive methods. The practice of narrative medicine brings new possibilities in the diagnosis and collection of classical history.