Ring melanoma of the anterior chamber angle: a report of fourteen cases

Tumor Profiles of Late Presentation Uveal Ring Melanoma With Novel Characteristics - A Case Series

Purpose

The purpose of this study was to investigate the clinical features, tumor characteristics, including histopathology and cytogenetic analysis, and management of patients with uveal ring melanoma in New Zealand.

Methods

A retrospective review was conducted on all uveal melanoma cases treated in a single national oncology center in New Zealand. The study period was from January 1, 2013 to December 31, 2022 (10 years). Written consent was obtained from all patients included in this case series.

Results

Uveal ring melanoma of ciliary body origin (n = 4) comprised 0.7% of all uveal melanomas (n = 571). Ethnicity distribution was three patients of New Zealand European ancestry and one patient of Chinese/Pasifika ancestry. Three patients (75%) were symptomatic at presentation (spontaneous hyphema, glaucoma, and cataract), whereas one was asymptomatic but subsequently developed painful refractory glaucoma. All eyes underwent enucleation. Three eyes had primary iris biopsies with subsequent enucleation for refractory glaucoma and pain and one eye underwent primary enucleation. All cases demonstrated malignant tumor characteristics including diffuse 270 to 360-degree ciliary body ring growth pattern, epithelioid-cell type and presence of either BAP-1 expression loss or gain of MYC gene. Two cases (50%) developed distant organ metastasis - liver, parotid gland, and breast. Of those, one patient was deceased at the time of follow-up whereas one had completed treatment for metastases.

Conclusions

Uveal ring melanoma is a rare tumor that is highly invasive and malignant. When detected, prompt definitive treatment should be advocated, and patient counselling should be given regarding the high risk of developing a painful, blind eye with increased risk of metastasis in the absence of treatment.

Choroidal Melanoma Masquerading as Central Serous Chorioretinopathy

PURPOSE

To determine the clinical features and outcomes of choroidal melanoma initially masquerading as central serous chorioretinopathy (CSCR).

DESIGN

Retrospective case series.

SUBJECTS

All patients with choroidal melanoma, initially misdiagnosed as CSCR elsewhere and evaluated by the Ocular Oncology Service at Wills Eye Hospital from 2004 to 2022, were included.

METHODS

A retrospective detailed review of patient charts and imaging was performed for all patients included in the study. Paired t tests and chi-squared tests were performed for data analysis.

MAIN OUTCOME MEASURES

The primary outcome measures included clinical characteristics, ultrasonography, OCT, fundus autofluorescence, fluorescein angiography, and indocyanine green angiography. The secondary outcome measures included treatment results, such as the final visual acuity, tumor control, radiation-related complications, and melanoma-related metastlasis and death.

RESULTS

There were 22 patients (mean age, 48 years; 16 men) in this cohort. The mean interval between initial CSCR diagnosis and suspicion of choroidal melanoma was 50 months (median, 50 months; range, 0-242 months). At tumor diagnosis, the melanoma was submacular in 16 (73%) patients and extramacular in 6 (27%) patients. The mean tumor thickness was 3.4 mm (median, 2.5 mm; range, 1.4-10.7 mm), and the mean basal diameter was 9.2 mm (median, 8.0 mm, range, 4.5-22.0 mm). Features enabling differentiation of choroidal melanoma from CSCR (affected versus unaffected eye) included choroidal thickness asymmetry (100% > 300 μm versus 21% > 300 μm; P = 0.005), ipsilateral choroidal surface irregularity (100% versus 0%; P < 0.001), loss of choroidal vascular detail on OCT (100% versus 0%; P < 0.001), presence of multiple pinpoint leaks on angiography (100% versus 0%; P < 0.001), and contralateral lack of autofluoresence abnormalities (75% versus 6%; P = 0.001). Management of the choroidal melanoma included plaque radiotherapy (19, 86%), enucleation (2, 9%), or treatment elsewhere (1, 5%). On follow-up (mean, 6 years), vision loss of ≥ 3 Snellen lines (9 patients, 47%), metastasis (3 patients, 14%), and death (1 patient, 5%) were noted.

CONCLUSIONS

Patients with presumed CSCR, especially if chronic, should be evaluated for a possible thin underlying choroidal melanoma with a dilated fundus examination and multimodal imaging.

Iris Ring Melanoma Presenting as Scleral Pigmentation

To report a patient with a very rare variant of iris melanoma that grows in the shape of a ring (ring melanoma). A 65-year-old patient was examined because of a pigmented lesion on the sclera. After a complete ophthalmic and ultrasound examination, a ring melanoma was diagnosed. Enucleation of the affected eye was performed, and histology report confirmed iris ring melanoma. This type of malignancy represents an exceedingly rare variant of uveal melanoma, and because of atypical clinical picture, it can be easily overlooked or misdiagnosed, which often delays adequate treatment. Gonioscopy, transillumination, and ultrasound help us to recognize and diagnose ring melanoma. Suspicion should be raised with a clinical picture that shows unilateral pigmentary glaucoma. The objective of this presentation is to describe and outline the challenging diagnosis and management of this rare disease entity.

Underlying Ciliary Body Uveal Melanoma in a Patient with Chronic Lymphocytic Leukemia Presenting for Hyphema

(1) Background: Ciliary body uveal melanoma is a rare subtype of uveal melanoma which comprises 3-5% of melanomas, an immunogenic cancer, and can present multifaceted initial clinical manifestations, masquerading as various ocular pathologies. Chronic lymphocytic leukemia (CLL) presents immunodeficiency and risk for the development of a secondary malignancy, with Bruton's tyrosine kinase inhibitor treatment having a mutagenic effect and a secondary anti-platelet aggregation effect. We present the case of a 65-year-old patient undergoing treatment for CLL with ibrutinib who presented with recurrent hyphema that masked an underlying, inferiorly situated, ciliary body uveal melanoma; (2) Methods: Retrospective case review; (3) Results: An ophthalmological examination together with imaging via mode B ultrasound and contrast-enhanced magnetic resonance imaging resulted in the clinical and imagistic diagnosis of a ciliary body uveal melanoma. A pathological examination of the enucleated eye confirmed the diagnosis. Postoperative tumoral reoccurrence was not detected for 1½ years, however, CLL immunosuppression worsened with admission for severe COVID-19 disease. (4) Conclusions: CLL patient screening for melanoma should also include detailed ophthalmological examinations, which could also include ultrasound ophthalmological imaging. The avoidance of uveal melanoma metastatic disease is paramount for patient survival. CLL manifests additional profound immunosuppression.

Brachytherapy or enucleation in ring melanoma patients: which is better? Preliminary results of the authors' own experiences

Purpose

A retrospective evaluation of effectiveness of brachytherapy or enucleation in treatment of rare form of uveal melanoma: ring melanoma.

Material and methods

Analysis comprised 49 patients treated from 2000 to 2019 for ring melanoma involving ciliary body. In 15 patients, primary treatment consisted of brachytherapy (¹⁰⁶Ru or ¹²⁵I), whereas in 34 patients, eyeballs were enucleated. The evaluation concerned differences between analyzed groups relating to the clinical and histopathological features as well as overall survival, cancer-specific overall survival, and disease-free survival.

Results

No significant differences between the analyzed groups were found with regards to clinical and histopathological features, apart from intra-ocular pressure (increased in the enucleation group). Kaplan-Meier analysis did not reveal any significant differences between the group treated with enucleation and the group undergoing brachytherapy, both with regards to overall survival (p = 0.325) and cancer-specific overall survival (p = 0.477). A significant difference was observed in disease-free survival (p = 0.009), which was significantly shorter in the group undergoing brachytherapy. In the analysis of parameters of the applied brachytherapy, no significant differences between patients with and without local recurrence were found. Mean observation period was 350.8 weeks (range, 24-996 weeks, SD = 231.6). A local recurrence occurred in 11 (22.4%) patients, including 3 (6.1%) in enucleation and 8 (16.3%) after brachytherapy groups. Metastasis developed in 11 (22.4%) cases after a mean follow-up of 133 weeks (33.25 months), range 3-655 weeks.

Conclusions

Preliminary observations may suggest that brachytherapy in this rare form of uveal melanoma, such as ring melanoma involving the ciliary body, may be taken into consideration as a useful alternative to enucleation. However, the confirmation of such an approach requires a larger patients’ group to be gathered, and also a longer follow-up period. This is especially important in patients with a good baseline visual acuity in the affected eye, or when the neoplasm is present in the remaining eye with vision.

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.

Glaucoma secondary to intraocular tumors: mechanisms and management

PURPOSE OF REVIEW

Glaucoma secondary to intraocular tumors is important to consider in eyes with a known tumor and those with unilateral or refractory glaucoma. The purpose of this review is to discuss the mechanisms and management of intraocular tumors with related secondary glaucoma.

RECENT FINDINGS

Several intraocular tumors can lead to glaucoma, including iris melanoma, iris metastasis, iris lymphoma, trabecular meshwork melanoma, choroidal melanoma, choroidal metastasis, retinoblastoma, and medulloepithelioma. The mechanisms for glaucoma include solid tumor invasion into the angle, tumor seeding into the angle, angle closure, and iris neovascularization. Management of the tumor can lead to resolution of glaucoma. Management of the secondary glaucoma may involve medical therapy, transscleral cyclophotocoagulation, laser trabeculoplasty, and potentially antivascular endothelial growth factor therapy. Minimally invasive glaucoma surgery (MIGS) can be considered for eyes with treated, regressed posterior segment malignancies if there is no iris or ciliary body involvement. Importantly, avoidance of MIGS, filtering, or shunting surgery in eyes with active malignancies is emphasized.

SUMMARY

Intraocular tumors can produce secondary glaucoma. Treatment of the primary tumor can sometimes resolve the glaucoma. Topical, oral, or laser therapies can be considered. Avoidance of MIGS, filtering, or shunting surgery is advised until the malignancy is completely regressed.

A Case of Iris Melanocytoma Demonstrating Diffuse Melanocytic Proliferation with Uncontrolled Intraocular Pressure

We report a rare case with histologically proven melanocytoma of the iris that demonstrated diffuse melanocytic proliferation with uncontrolled secondary glaucoma and investigate the etiology of the intraocular pressure elevation. The patient was a 78-year-old man with a history of darkened iris of his left eye. The intraocular pressure was 39 mm Hg. A slit-lamp examination showed a diffuse darkened iris, and a gonioscopic examination revealed open angle with circumferential heavy pigmentation. There was no pigment dispersion of the anterior chamber and no pigment deposition of the cornea. We suspected malignant ring melanoma in the left eye and enucleated it. The globe was examined with light and electron microscopy. Light microscopy revealed the presence of heavily pigmented tumor cells in the iris, ciliary body, trabecular meshwork, and Schlemm's canal. A bleached preparation showed large tumor cells with central and paracentral nuclei without mitosis. Electron microscopy of the trabecular meshwork revealed melanin-bearing tumor cells invading the intertrabecular spaces, and the melanin granules were not phagocytosed in the trabecular cells. The mechanical obstruction of the aqueous flow by the tumor cells may be a major cause of secondary glaucoma in eyes with iris melanocytoma presenting diffuse proliferation.

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.

[Plaque radiotherapy for anterior uveal melanomas]

AIM

To determine the effectiveness of plaque radiation therapy for anterior uveal melanomas and to evaluate the risk and frequency of complications at different time intervals after the treatment.

MATERIAL AND METHODS

During 2010-2013 a total of 30 patients (10 male, 20 female) aged 11-73 (50 years on the average) with iris or iridociliary melanomas were treated with Ru-106 and Sr-90 ophthalmic plaques. In 8 patients the brachytherapy was preceded by local tumor excision. Morphological diagnosis was verified in 10 patients (8 iridectomies, 2 enucleations), of them 8 cases turned out to be spindle cell melanomas and the other 2--mixed cell melanomas. Follow-up period ranged from 1 to 54 months with the median of 13,5 months.

RESULTS

Tumor regression was achieved in all cases. Enucleation had to be performed in 2 patients due to cornea and sclera necrosis. In the early post-brachytherapy period (up to 1 month) the most frequent radiation-related complications were keratopathy and uveitis (8 and 6 patients correspondingly). In patients observed for up to 3 months (28 patients) these were keratopathy and cataract (8 and 5 patients correspondingly). In the long-term (over 6 months) cataract predominated (17 patients). At the end of the study all patients were alive. Metastatic disease was diagnosed in one patient 30 months after the treatment.

CONCLUSIONS

The results of the present clinical study confirm the effectiveness of brachytherapy for iris and iridociliary melanomas, which implies that tumor is well locally controlled and radiation-related complications are moderate and curable. This method of local tumor destruction can be another alternative to enucleation in cases when local tumor excision cannot be performed.

Secondary glaucoma as initial manifestation of uveal melanoma

PURPOSE

Secondary glaucoma can be induced by a variety of local ocular problems. Intraocular tumors may initially present as secondary glaucoma.

METHODS

8 consecutive patients with secondary glaucoma were found to have uveal melanoma. Thorough examination included detailed history, fundus examination with scleral depression, B scan ultrasonography, and CT/MRI scanning techniques.

RESULTS

A single case presented with spontaneous hyphema, two patients presented with secondary glaucoma, extraocular melanoma and metastases, a single case was found to have angle block by an iridociliary ring melanoma and 4 cases presented with neovascular glaucoma. Enucleation was necessary in all 8 cases.

CONCLUSIONS

General ophthalmologists should be aware of these rare initial manifestations of intraocular tumors as secondary glaucoma. Enucleation would be recommended in most cases of intraocular malignancy manifesting as secondary glaucoma. One should be extremely cautious in doing a penetrating surgery in such cases.

The CT appearance of a corneal melt: report of 2 cases

When the cornea of the eye dissolves, most commonly secondary to infection or trauma, the ventral wall of the anterior chamber of the eye is no longer supported and thus bulges forward, enlarging the anterior chamber volume. This is referred to as a corneal melt, and it has a unique CT appearance that has not been previously described.

Glaucomas Secondary to Intraocular Melanomas

Intraocular melanomas are not common entities but often lead to secondary glaucoma. Intraocular melanomas should be considered in the differential diagnosis of patients with unilateral glaucoma. Occasionally, the workup of unilateral glaucoma leads to a diagnosis of an intraocular melanoma. Intraocular melanomas represent the majority of intraocular tumors. The prevalence of intraocular melanomas as well as associated secondary glaucomas will be reviewed. The workup needed for unilateral glaucoma will be covered in detail. Treatment options for secondary glaucomas include topical and oral medications as well as argon laser trabeculoplasty and transscleral cyclophotocoagulation.

Massive extraocular extension and parotid lymph node metastasis of uveal melanoma

A 22-year-old man, diagnosed with unilateral glaucoma and treated with trabeculectomy 6 years earlier, presented with an epibulbar nodule of 6 months' duration. MRI displayed intra- and extraocular tumor, and gross invasion of the medial rectus muscle. Biopsy demonstrated uveal melanoma, and staging revealed enhancing ipsilateral parotid lymph nodes. Orbital exenteration and parotidectomy with selective neck dissection were performed. The tumor infiltrated superficial parotid nodes and extended into the parotid gland. The site of tumor origin is speculative, but a ring melanoma of the anterior chamber angle is suspected. Lymph node metastasis of uveal melanoma is rare; to our knowledge, this is the most advanced of the few reported cases.

Mélanome annulaire révélé par un hyphéma spontané

INTRODUCTION

Ring melanoma is a rare form of uveal melanoma characterized by the circumferential involvement of the ciliary body. Unilateral chronic and refractory glaucoma is a classic circumstance of diagnosis.

OBSERVATION

We report a case of ring melanoma revealed by acute intraocular hypertonia secondary to spontaneous hyphema. Iris and iridocorneal angle were diffusely invaded by the tumor. The fundus was masked but B-scan ultrasonography revealed a voluminous ciliochoroidal tumor. The patient had been enucleated. Pathological examination confirmed the diagnosis of ring melanoma. The tumor involved angle structures. The patient died 1 year later because of metastasis.

DISCUSSION

Acute or chronic ocular hypertonia is a classic but rare circumstance of uveal melanoma diagnosis. Many mechanisms exist: neovascular glaucoma, secondary angle closure, involvement of angle structures, and trabecular obstruction by tumor cells or pigment. Acute intraocular hypertonia secondary to hyphema is more exceptional. Our observation highlights that apart from the classic situation of acute angle closure glaucoma, intraocular hypertonia requires meticulous fundus examination, if necessary using B-scan ultrasonography.

The Use of Ultrasound Biomicroscopy in the Evaluation of Anterior Segment Tumors and Simulating Conditions

PURPOSE

To report the ultrasound biomicroscopy (UBM) findings of anterior segment tumors and simulating conditions.

METHODS

Thirty-five patients underwent UBM. Of those, 16 had histopathologically or cytopathologically diagnosed tumors, and 19 had clinically diagnosed lesions.

RESULTS

The study material comprised 13 iris pigment epithelial (IPE) cysts, 7 ciliary body melanomas, 4 iris melanomas, 4 iris nevi, 3 intraocular invasions of conjunctival squamous cell carcinoma, 2 ring melanomas of the anterior chamber angle, 1 medulloepithelioma and 1 pars plana cyst. On UBM, all IPE cysts presented as cystic lesions with a thin cyst wall and no solid components. All ciliary body melanomas showed low to medium reflectivity, with cavitation in one case and extraocular extension in another. Iris melanomas presented as anterior (stromal) iris lesions with medium to high internal reflectivity. There was irregularity and convex bowing of the posterior iris plane in iris melanomas, a feature not seen in iris nevi. Intraocular invasion of conjunctival squamous cell carcinoma was evidenced as areas of medium to high reflectivity in the ciliary body and iris, loss of the acute angle shape and highly reflective spots in the anterior chamber.

CONCLUSIONS

UBM was particularly useful in the diagnosis of IPE cysts, in the visualization of small ciliary body melanomas, in the differentiation of iris melanomas from iris nevi and in the demonstration of intraocular invasion from conjunctival squamous cell carcinoma.

Iris ring melanoma: fine needle biopsy

AIMS

To delineate the diagnostic accuracy of fine needle biopsy in iris ring melanoma and determine the tumour related mortality of this neoplasm.

METHODS

A retrospective analysis of 22 patients with iris melanomas that involve the entire 360 degrees of the anterior chamber angle.

RESULTS

Iris ring melanomas were correctly diagnosed in all cases. In 11 of 16 cases (69%) a fine needle biopsy performed 180 degrees away from the main mass was positive for an iris ring melanoma. The tumour related mortality in iris ring melanoma cases was four of 22 patients (18%). Actuarial survival analysis showed a 10 year mortality (Kaplan-Meier) of 15%.

CONCLUSION

A fine needle aspiration biopsy can be used to diagnose an iris ring melanoma. Iris ring melanomas have significant mortality compared with focal tumours.

Anterior segment tumors: current concepts and innovations

The most common anterior segment tumors are primary neuroepithelial cysts, uveal melanomas, metastatic tumors, and benign tumors. In the majority of cases, the diagnosis can be made utilizing a careful clinical history and ocular examination. Ultrasound examination (low and high frequency) has become an indispensable tool used to determine tumor extension and involvement of the surrounding structures. In particular, high-frequency ultrasound has been used to uncover iris pigment epithelial cysts, to allow for the diagnosis of small ciliary body melanomas, and to measure tumors for plaque radiation planning. Whereas fluorescein angiography and computerized tomography have come to play a limited role, fine-needle aspiration biopsy has been found to be quite helpful in selected cases. Once the diagnosis is established, treatment decisions depend on the tumors' location, size, local extension, patterns of growth, and secondary complications. Most anterior segment tumors can be observed for growth prior to treatment. Other options include local resection (iridectomy, lamellar sclerouvectomy, or eye-wall resection) and radiation (ophthalmic plaque or external beam). Enucleation is typically employed if these eye- and vision-sparing treatments are not possible and for uncontrollable secondary glaucoma. This review examines the unique role of high-frequency ultrasonography for the diagnosis and treatment of anterior segment tumors as well as an overview of clinical practice.

Ring melanoma of the ciliary body: report on twenty-three patients

BACKGROUND

Ring melanoma of the ciliary body is a rare variant of uveal melanoma that has a poor prognosis. Only isolated cases have been reported in the literature.

METHODS

A retrospective review of the clinical features, management, histopathology, and prognosis of 23 consecutive patients with ring melanoma of the ciliary body was performed.

RESULTS

Of 8,800 patients with uveal melanoma treated on the Oncology Service at Wills Eye Hospital over a 25-year period, only 23 patients (0.3%) were found to have ring melanoma of the ciliary body. The mean patient age was 59 years (median, 63 years; range, 8-81 years). The only visual symptom was blurred vision in 17 patients (74%), and the other six patients (26%) were asymptomatic. At the initial presentation elsewhere, melanoma was recognized in 13 cases (57%). In the remaining 10 cases (43%), the initial clinical diagnosis was glaucoma in three (13%), iris nevus in three (13%), cataract in two (9%), ciliary body detachment in one (4%), and iridocyclitis in one (4%). The patients were observed elsewhere for a mean of 3 months before the diagnosis of melanoma was suspected and referral to Oncology Service was made. On examination, the tumor involved a mean of eight clock hours of the ciliary body. Seven patients (30%) had complete circumferential (360 degrees) involvement of the ciliary body, and 16 (70%) had incomplete (180-360 degrees) ring involvement. The mean tumor thickness was 8 mm. Associated findings included neovascularization of the iris in one case (4%), shallow anterior chamber in 11 (48%), anterior chamber inflammation in five (22%), cataract in nine (39%), lens indentation in eight (35%), and lens subluxation in three (13%). A prominent episcleral (sentinel) vessel (17 cases, 74%), multilobulation of the mass (19 cases, 83%), blockage of light on transillumination (23 cases, 100%), and ultrasonographic hollowness with intrinsic pulsations (23 cases, 100%) were important features differentiating this tumor from simulating conditions. The tumor was managed with enucleation in all 23 patients. Histopathologic studies revealed epithelioid cell-type melanoma in two patients (9%), mixed cell-type in 17 (74%), and spindle cell-type in four (17%). Extraocular extension was present in eight patients (35%). Metastasis developed in 12 of 23 patients (52%) after a mean follow-up of 55 months.

CONCLUSIONS

Ring melanoma of the ciliary body is a rare tumor that can remain hidden from ophthalmoscopic examination. Certain features, such as prominent episcleral sentinel vessels, multilobulation of the mass, light blockage on transillumination, and ultrasonographic hollowness with intrinsic vascular pulsations, suggest the diagnosis. The life prognosis is poor.