Current appraisal of conjunctival melanocytic tumors: classification and treatment

Pediatric conjunctival melanoma: A comprehensive case report and literature review

Purpose

This case report aims to present a rare instance of conjunctival melanoma in a 5-year-old patient and contribute to the limited body of knowledge on pediatric conjunctival melanoma. The purpose is to understand the characteristics, diagnosis, and management of this uncommon malignancy in young individuals.

Observations

The case describes a 5-year-old female with a progressively growing pigmented conjunctival lesion. The lesion was observed to be located on the temporal conjunctiva of the right eye and displayed distinctive features, including feeder vessels. Imaging revealed specific dimensions of the lesion and ruled out deeper invasions. Histopathological examination revealed architectural and cytologic atypia, positive immunohistochemical staining for HMB-45, and a Ki67 proliferation index of 20 %, confirming the diagnosis of conjunctival melanoma.

Conclusions

Conjunctival melanoma, an uncommon malignancy even more so in pediatric patients, typically presents with pigmented growths and feeder vessels. This case underscores the need for thorough diagnosis and early intervention, as conjunctival melanoma can lead to devastating outcomes. The rarity of such cases limits our understanding of their etiology and progression. This case contributes to the literature on pediatric conjunctival melanoma and reinforces the importance of vigilance in detecting and managing ocular pigmented lesions in children.

Genetic characterization of advanced conjunctival melanoma and response to systemic treatment

BACKGROUND

Conjunctival melanoma is a rare type of ocular melanoma, which is prone to local recurrence and metastasis and can lead to patient death. Novel therapeutic strategies have revolutionized cutaneous melanoma management. The efficacy of these therapies in conjunctival melanoma, however, has not been evaluated in larger patient cohorts.

METHODS

In this multi-center retrospective cohort study with additional screening of the ADOREG database, data were collected from 34 patients with metastatic conjunctival melanoma who received targeted therapy (TT) (BRAF ± MEK inhibitors) or immune checkpoint inhibitors (ICI) (anti-PD-1 ± anti-CTLA4). In 15 cases, tissue was available for targeted next-generation-sequencing (611 genes) and RNA sequencing. Driver mutations, tumor mutational burden, copy number variations and inflammatory/IFNγ gene expression signatures were determined.

RESULTS

Genetic characterization identified frequent BRAF (46.7%, 7/15), NRAS (26.7%, 4/15), NF1 (20%, 3/15), and TERT promoter (46.7%, 7/15) mutations. UV associated C>T and CC>TT mutations were common. Median follow-up time after start of first TT or ICI therapy was 13.2 months. In 26 patients receiving first-line ICI, estimated one-year progression-free survival (PFS) rate was 42.0%, PFS and overall survival (OS) 6.2 and 18.0 months, respectively. First-line TT was given to 8 patients, estimated one-year PFS rate was 54.7%, median PFS and OS 12.6 and 29.1 months, respectively.

CONCLUSIONS

Our findings support the role of UV irradiation in conjunctival melanoma and the genetic similarity with cutaneous melanoma. Conjunctival melanoma patients with advanced disease benefit from both targeted therapies (BRAF ± MEK inhibitors) and immune checkpoint inhibitors.

Primary acquired melanosis/melanoma: utility of conjunctival map biopsy

AIM

To assess the role of map biopsy in patients with conjunctival primary acquired melanosis (PAM)/melanoma.

METHODS

Retrospective case series of 400 conjunctival biopsy samples of 51 unique patients in a tertiary referral centre.

RESULTS

Each patient underwent one diagnostic biopsy and several additional map biopsies (range 2-7) providing a total of 400 samples for the analysis (55 diagnostic biopsies, 345 map biopsies). The median age was 63 years old (range 20-88) with women representing 67% of the cases. Histopathological findings were graded as negative for melanosis/normal (grade 0), melanosis without atypia (grade 1), melanosis with mild atypia (grade 2), melanosis with severe atypia (grade 3) or invasive melanoma (grade 4). Clinicopathologic concordance was observed in the majority of the map biopsies (313, 91%) (positive: clinical+/path+ (57,17%), negative: clinical-/path- (256, 74%)). Three discordant samples (clinical-/path+) represented PAM sine pigmento. The histopathological spectrum of atypia was absent (40, 73%) or limited (11, 20%) in the majority of cases with tendency to cluster as low-grade or high-grade atypia. Map biopsy led to the identification of six patients (11%) with severe atypia, requiring topical mitomycin (MMC). Similarly, in 29 cases, periodic observation without topical MMC was recommended. One case of invasive melanoma transformation occurred in the MMC-treated group.

CONCLUSIONS

Map biopsy enhances overall assessment of the anatomic and pathologic extent, impacting use of adjuvant topical chemotherapy. In absence of map biopsy, it would be impossible to diagnose PAM sine pigmento. Additional corroborative work is needed to validate our observations.

NF1 mutations in conjunctival melanoma

Background

Conjunctival melanoma is a potentially deadly eye tumour. Despite effective local therapies, tumour recurrence and metastasis remain frequent. The genetics of conjunctival melanomas remain incompletely understood.

Methods

A large cohort of 63 conjunctival melanomas was screened for gene mutations known to be important in other melanoma subtypes by targeted next-generation sequencing. Mutation status was correlated with patient prognosis.

Results

Frequent mutations in genes activating the MAP kinase pathway were identified. NF1 mutations were most frequent (n = 21, 33%). Recurrent activating mutations were also identified in BRAF (n = 16, 25%) and RAS genes (n = 12, 19%; 11 NRAS and 1 KRAS).

Conclusions

Similar to cutaneous melanomas, conjunctival melanomas can be grouped genetically into four groups: BRAF-mutated, RAS-mutated, NF1-mutated and triple wild-type melanomas. This genetic classification may be useful for assessment of therapeutic options for patients with metastatic conjunctival melanoma

Targeting of the MAPK and AKT pathways in conjunctival melanoma shows potential synergy

PURPOSE

Conjunctival melanoma (CM) is a rare but lethal form of cancer. Similar to cutaneous melanoma, CM frequently carries activating mutations in BRAF and NRAS. We studied whether CM as well as conjunctival benign and premalignant melanocytic lesions express targets in the mitogen-activated protein kinase (MAPK) and AKT pathways, and whether specific inhibitors can suppress CM growth in vitro.

METHODS

131 conjunctival lesions obtained from 129 patients were collected. The presence of BRAF V600E mutation and expression of phosphorylated (p)-ERK and p-AKT were assessed by immunohistochemistry. We studied cell proliferation, phosphorylation, cell cycling and apoptosis in three CM cell lines using two BRAF inhibitors (Vemurafenib and Dabrafenib), a MEK inhibitor (MEK162) and an AKT inhibitor (MK2206).

RESULTS

The BRAF V600E mutation was present in 19% of nevi and 26% of melanomas, but not in primary acquired melanosis (PAM). Nuclear and cytoplasmic p-ERK and p-AKT were expressed in all conjunctival lesions. Both BRAF inhibitors suppressed growth of both BRAF mutant CM cell lines, but only one induced cell death. MEK162 and MK2206 inhibited proliferation of CM cells in a dose-dependent manner, and the combination of these two drugs led to synergistic growth inhibition and cell death in all CM cell lines.

CONCLUSION

ERK and AKT are constitutively activated in conjunctival nevi, PAM and melanoma. While BRAF inhibitors prohibited cell growth, they were not always cytotoxic. Combining MEK and AKT inhibitors led to more growth inhibition and cell death in CM cells. The combination may benefit patients suffering from metastatic conjunctival melanoma.

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.

Epithelial Inclusion Cyst in Conjunctival Melanoma

Conjunctival melanoma is the second most common conjunctival malignancy. Its differential diagnosis with other conjunctival melanocytic neoplasms is inherently difficult. The presence of epithelial cysts is a useful feature in conjunctival tumors and favors a benign lesion. Herein 2 cases of conjunctival melanoma with cysts are presented. To the best of our knowledge, this is the first series of conjunctival melanoma with epithelial inclusion cysts. This series emphasizes the importance of considering several malignant features when reviewing conjunctival melanocytic lesions, as malignancy can exist even in the presence of epithelial inclusion cysts.

TERT promoter mutation is uncommon in acral lentiginous melanoma

BACKGROUND

Melanoma is a heterogeneous group of diseases with distinct sets of genetic changes. Recurrent and mutually exclusive C>T or CC>TT transition mutations were identified in the promoter region of the reverse transcriptase catalytic subunit of the telomerase gene (TERT) in melanoma recently, and it was suggested that they enhanced the expression of TERT gene and played important roles in the melanoma pathogenesis. These mono or di-nucleotide transitions were ultraviolet (UV)-signature mutations.

METHODS

In this study, polymerase chain reaction and direct sequencing of TERT promoter using formalin-fixed and paraffin-embedded tissue was performed to investigate whether these UV-signature mutations were also present in acral lentiginous melanoma.

RESULTS

TERT promoter mutation was identified in only 2 of the 32 cases (6%) of acral lentiginous melanomas while it was identified in 3 of the 9 cases (33%) of non-acral cutaneous melanomas. The difference was statistically significant (p = 0.028).

CONCLUSIONS

The rarity of TERT promoter mutation in the acral lentiginous melanoma was consistent with the supposed role of UV light in the melanoma pathogenesis and also corroborated the view that acral lentiginous melanomas have a different pathogenesis with the melanomas from sun-exposed sites.

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.

TERT promoter mutations in ocular melanoma distinguish between conjunctival and uveal tumours

BACKGROUND

Recently, activating mutations in the TERT promoter were identified in cutaneous melanoma. We tested a cohort of ocular melanoma samples for similar mutations.

METHODS

The TERT promoter region was analysed by Sanger sequencing in 47 uveal (ciliary body or choroidal) melanomas and 38 conjunctival melanomas.

RESULTS

Mutations of the TERT promoter were not identified in uveal melanomas, but were detected in 12 (32%) conjunctival melanomas. Mutations had a UV signature and were identical to those found in cutaneous melanoma.

CONCLUSION

Mutations of TERT promoter with UV signatures are frequent in conjunctival melanomas and favour a pathogenetic kinship with cutaneous melanomas. Absence of these mutations in uveal melanomas emphasises their genetic distinction from cutaneous and conjunctival melanomas.

Conjunctival melanomas harbor BRAF and NRAS mutations and copy number changes similar to cutaneous and mucosal melanomas

PURPOSE

Conjunctival melanoma is a rare but potentially deadly tumor of the eye. Despite effective local therapies, recurrence and metastasis remain frequent. Once the tumor has metastasized, treatment options are limited and the prognosis is poor. To date, little is known of the genetic alterations in conjunctival melanomas.

EXPERIMENTAL DESIGN

We conducted genetic analysis of 78 conjunctival melanomas, to our knowledge the largest cohort reported to date. An oncogene hotspot array was run on 38 samples, screening for a panel of known cancer-relevant mutations. Thirty tumors were analyzed for genome-wide copy number alterations (CNA) using array-based comparative genomic hybridization. Sanger sequencing of selected target mutations was conducted in all samples.

RESULTS

BRAF mutations were identified in 23 of 78 (29%) tumors. NRAS mutations, previously not recognized as relevant in conjunctival melanoma, were detected in 14 of 78 (18%) tumors. We found CNAs affecting various chromosomes distributed across the genome in a pattern reminiscent of cutaneous and mucosal melanoma but differing markedly from uveal melanoma.

CONCLUSIONS

The presence of NRAS or BRAF mutations in a mutually exclusive pattern in roughly half (47%) of conjunctival melanomas and the pattern of CNAs argue for conjunctival melanoma being closely related to cutaneous and mucosal melanoma but entirely distinct from uveal melanoma. Patients with metastatic conjunctival melanoma should be considered for therapeutic modalities available for metastatic cutaneous and mucosal melanoma including clinical trials of novel agents.

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.

Micro-Raman spectroscopy study of human pterygium and conjunctival melanocytic nevi

Pterygium, a common ophthalmic disease that is caused by fibrovascular growth of conjunctiva and conjunctival melanocytic nevi that is another conjunctival disease, are detected by Raman spectroscopy in the present study. We find that there is an obvious increase in the intensity at the peak of 1,583 cm(-1) that is assigned to C=C unsaturated fatty acids stretch of lipids in the pterygium tissue, and 1,639 cm(-1) also increased which belongs to amide I. Also, PCA (Principal Component Analysis) was used to classify the normal conjunctiva from the pterygium tissue. For the conjunctival melanocytic nevi, the intensity of Raman spectrum region between 1,550 cm(-1) and 1,650 cm(-1) that belong to protein has increased, which indicates that the content of protein in conjunctival melanocytic nevi is more richer than the normal ones.