Congenital uveal melanoma?

Congenital uveal malignant melanoma- A rare case report

Purpose

To report a rare case of congenital uveal malignant melanoma from Indian subcontinent in an infant with multiple cutaneous naevi and no distant metastasis.

Observation

An 8 month old male child presented with proptosis and black discoloration in the right eye since birth. Enucleation of the right eye was performed and specimen sent for histopathology and immunohistochemical analysis. Results were strongly suggestive of a malignant melanoma of uvea. No metastasis was found on MRI scan of brain, chest and abdomen. Patient is on close follow up and will be subjected to metastasis workup every 6 months.

Conclusion and importance

This entity of congenital uveal malignant melanoma is rather rare with very few reported cases across the globe and needs further understanding of its correct line of treatment.

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.

Exosomes: Insights from Retinoblastoma and Other Eye Cancers

Exosomes, considered as cell debris or garbage bags, have been later characterized as nanometer-sized extracellular double-membrane lipid bilayer bio-vesicles secreted by the fusion of vesicular bodies with the plasma membrane. The constituents and the rate of exosomes formation differ in different pathophysiological conditions. Exosomes are also observed and studied in different parts of the eye, like the retina, cornea, aqueous, and vitreous humor. Tear fluid consists of exosomes that are shown to regulate various cellular processes. The role of exosomes in eye cancers, especially retinoblastoma (RB), is not well explored, although few studies point towards their presence. Retinoblastoma is an intraocular tumor that constitutes 3% of cases of cancer in children. Diagnosis of RB may require invasive procedures, which might lead to the spread of the disease to other parts. Due to this reason, better ways of diagnosis are being explored. Studies on the exosomes in RB tumors and serum might help designing better diagnostic approaches for RB. In this article, we reviewed studies on exosomes in the eye, with a special emphasis on RB. We also reviewed miRNAs expressed in RB tumor, serum, and cell lines and analyzed the targets of these miRNAs from the proteins identified in the RB tumor exosomes. hsa-miR-494 and hsa-miR-9, upregulated and downregulated, respectively in RB, have the maximum number of targets. Although oppositely regulated, they share the same targets in the proteins identified in RB tumor exosomes. Overall this review provides the up-to-date progress in the area of eye exosome research, with an emphasis on RB.

Whole Exome Sequencing Identifies Candidate Genes Associated with Hereditary Predisposition to Uveal Melanoma

PURPOSE

To identify susceptibility genes associated with hereditary predisposition to uveal melanoma (UM) in patients with no detectable germline BAP1 alterations.

DESIGN

Retrospective case series from academic referral centers.

PARTICIPANTS

Cohort of 154 UM patients with high risk of hereditary cancer defined as patients with 1 or more of the following: (1) familial UM, (2) young age (<35 years) at diagnosis, (3) personal history of other primary cancers, and (4) family history of 2 or more primary cancers with no detectable mutation or deletion in BAP1 gene.

METHODS

Whole exome sequencing, a cancer gene panel, or both were carried out. Probands included 27 patients with familial UM, 1 patient with bilateral UM, 1 patient with congenital UM, and 125 UM patients with strong personal or family histories, or both, of cancer. Functional validation of variants was carried out by immunohistochemistry, reverse-transcriptase polymerase chain reaction, and genotyping.

MAIN OUTCOME MEASURES

Clinical characterization of UM patients with germline alterations in known cancer genes.

RESULTS

We identified actionable pathogenic variants in 8 known hereditary cancer predisposition genes (PALB2, MLH1, MSH6, CHEK2, SMARCE1, ATM, BRCA1, and CTNNA1) in 9 patients, including 3 of 27 patients (11%) with familial UM and 6 of 127 patients (4.7%) with a high risk for cancer. Two patients showed pathogenic variants in CHEK2 and PALB2, whereas variants in the other genes each occurred in 1 patient. Biallelic inactivation of PALB2 and MLH1 was observed in tumors from the respective patients. The frequencies of pathogenic variants in PALB2, MLH1, and SMARCE1 in UM patients were significantly higher than the observed frequencies in noncancer controls (PALB2: P = 0.02; odds ratio, 8.9; 95% confidence interval, 1.5-30.6; MLH1: P = 0.04; odds ratio, 25.4; 95% confidence interval, 1.2-143; SMARCE1: P = 0.001; odds ratio, 2047; 95% confidence interval, 52-4.5e15, respectively).

CONCLUSIONS

The study provided moderate evidence of gene and disease association of germline mutations in PALB2 and MLH1 with hereditary predisposition to UM. It also identified several other candidate susceptibility genes. The results suggest locus heterogeneity in predisposition to UM. Genetic testing for hereditary predisposition to cancer is warranted in UM patients with strong personal or family history of cancers, or both.

Congenital choroidal melanocytoma in a child with ocular melanocytosis

A 1-day-old child was brought to the clinic for evaluation of enlarged right eye (OD). On examination, OD showed buphthalmos with diffuse scleral melanocytosis, fleshy blackish-brown extrascleral mass with corneal extension, and secondary glaucoma. Anterior segment evaluation revealed darkly pigmented iris and fundus evaluation OD revealed a darkly pigmented choroidal lesion. The left eye was within normal limits. A clinical diagnosis of choroidal melanocytoma with ocular melanocytosis was made. Enucleation OD followed by orbital implant was performed. Histopathology showed features of diffuse ocular melanocytosis involving limbus, iris, ciliary body, choroid, sclera, optic nerve head, optic nerve sheath, along with choroidal melanocytoma with extrascleral tumour extension. We presume that choroidal melanocytoma may have arisen from ocular melanocytosis.

Uveal melanoma: relatively rare but deadly cancer

Although it is a relatively rare disease, primarily found in the Caucasian population, uveal melanoma is the most common primary intraocular tumor in adults with a mean age-adjusted incidence of 5.1 cases per million per year. Tumors are located either in iris (4%), ciliary body (6%), or choroid (90%). The host susceptibility factors for uveal melanoma include fair skin, light eye color, inability to tan, ocular or oculodermal melanocytosis, cutaneous or iris or choroidal nevus, and BRCA1-associated protein 1 mutation. Currently, the most widely used first-line treatment options for this malignancy are resection, radiation therapy, and enucleation. There are two main types of radiation therapy: plaque brachytherapy (iodine-125, ruthenium-106, or palladium-103, or cobalt-60) and teletherapy (proton beam, helium ion, or stereotactic radiosurgery using cyber knife, gamma knife, or linear accelerator). The alternative to radiation is enucleation. Although these therapies achieve satisfactory local disease control, long-term survival rate for patients with uveal melanoma remains guarded, with risk for liver metastasis. There have been advances in early diagnosis over the past few years, and with the hope survival rates could improve as smaller tumors are treated. As in many other cancer indications, both early detection and early treatment could be critical for a positive long-term survival outcome in uveal melanoma. These observations call attention to an unmet medical need for the early treatment of small melanocytic lesions or small melanomas in the eye to achieve local disease control and vision preservation with the possibility to prevent metastases and improve overall patient survival.