Topography and clinical features of iris melanoma

Iris melanoma in an Australian cohort

BACKGROUND

To report the clinicopathological features and epidemiology of iris melanoma in Queensland, Australia.

METHODS

This was a retrospective study of 86 patients with iris melanoma treated between 2001 and 2022 at the Queensland Ocular Oncology Service, Brisbane, Australia. Main outcome measures included demographics, clinical and phenotypic features, age-adjusted incidence and relative survival.

RESULTS

Eighty-six patients (63% female) were included. Mean age was 54 years (range 17-82 years). The majority of patients (97%) were Caucasian, with blue eyes, fair skin and Fitzpatrick Skin Type I or II. Demographic features and clinical history showed a tendency for high ultraviolet radiation (UVR) exposure in the cohort. Histopathology was available in 69 cases (82%), and of these, 77% tumours were of spindle cell origin, with low-risk genetic profiles. Patients were followed for a mean of 8 years (median 7, range 1-21 years) after diagnosis, and only one case of metastasis was documented.

CONCLUSIONS

The association of iris freckles, history of UVR exposure and dermatologic findings supports the role of UVR in iris melanoma. Occupation and avocation history, as well as evaluation of iris freckles may offer an easily accessible way of stratifying the risk of an individual for development of UVR-related uveal melanoma.

Predictive model for iris melanoma

AimTo develop a predictive model for the diagnosis of iris melanoma.

METHODS

Retrospective consecutive case series that included 100 cases of pathologically confirmed iris melanoma and 112 cases of Iris naevus, either pathological confirmation or documented stability of >1 year. Patient demographic data, features of clinical presentation, tumour characteristics and follow-up were collected. Iris melanoma with ciliary body extension was excluded. Lasso logistic regression with 10-fold cross-validation was used to select the tuning parameter. Discrimination was assessed with the area under the curve (AUC) and calibration by a plot.

RESULTS

There was a significant asymmetry in the location of both nevi and melanoma with preference for inferior iris quadrants (83, 74%) and (79, 79%), respectively (p=0.50). Tumour seeding, glaucoma and hyphaema were present only in melanoma. The features that favoured the diagnosis of melanoma were size (increased height (OR 3.35); increased the largest basal diameter (OR 1.64)), pupillary distortion (ectropion uvea or corectopia (OR 2.55)), peripheral extension (angle or iris root involvement (OR 2.83)), secondary effects (pigment dispersion (OR 1.12)) and vascularity (OR 6.79). The optimism-corrected AUC was 0.865. The calibration plot indicated good calibration with most of the points falling near the identity line and the confidence band containing the identity line through most of the range of probabilities.

CONCLUSIONS

The predictive model provides direct diagnostic prediction of the lesion being iris melanoma expressed as probability (%). Use of a prediction calculator (app) can enhance decision-making and patient counselling. Further refinements can be undertaken with additional datasets, forming the basis for automated diagnosis.

Pediatric ocular melanoma: a collaborative multicenter study and meta-analysis

PURPOSE

To investigate clinical manifestations and prognoses in pediatric patients (≤12 years old) with ocular melanoma.

METHODS

This was a retrospective, multicenter cohort study with individual participant data (IPD) meta-analysis pooling available published cases, and unpublished cases from an international collaboration of seven ocular oncology centers.

RESULTS

There were 133 eyes of 133 pediatric patients with choroidal or ciliary body (n = 66 [50%]), iris (n = 33 [25%]), conjunctival (n = 26 [19%]), and eyelid (n = 8 [6%]) melanoma. Overall, the mean patient age at presentation was 7 years (median, 8; range, 1-12 years), with 63 males (49%). The mean age by tumor site was 6.50 ± 3.90, 7.44 ± 3.57, 9.12 ± 2.61, and 5.63 ± 2.38 years, for choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively (P = 0.001). Association with ocular melanocytosis was seen in 15%, 11%, 4%, and 0%, respectively (P = 0.01). Frequency of ocular melanoma family history did not vary by tumor site (7%, 17%, 9% and 12%, resp. [P = 0.26]). After mean follow-up of 74, 85, 50, and 105 months (P = 0.65), metastasis was seen in 12%, 9%, 19%, and 13% of choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively. Death was reported in 5%, 3%, 8%, and 0%, respectively, with survival analysis indicating higher mortality in choroidal/ciliary body and conjunctival melanoma patients.

CONCLUSIONS

Ocular melanoma in the pediatric population is rare, with unique clinical features and outcomes. Iris melanoma accounts for about one-third of pediatric uveal melanoma cases.

Clinical Outcomes in AYAs (Adolescents and Young Adults) Treated with Proton Therapy for Uveal Melanoma: A Comparative Matching Study with Elder Adults

OBJECTIVE

The aim of this study was to compare the clinical outcomes of adolescents and young adults (AYAs) with those of elder adult patients treated with proton therapy (PT) for uveal melanoma (UM).

MATERIAL AND METHODS

A retrospective, comparative study was conducted in UM patients who underwent PT at the Ocular Oncology Unit of the Jules-Gonin Eye Hospital (University of Lausanne, Lausanne, Switzerland) and the Paul Scherrer Institute (PSI); (Villigen, Switzerland) between January 1997 and December 2007. Propensity score matching (PSM) was used to select for each AYA (between 15-39 years old) an elder adult patient (≥40 years) with similar characteristics. We assessed ocular follow-up, local tumor control, metastasis incidence, and overall and relative survival (OS and RS). Non-terminal outcomes were then compared between the two groups using competing risk survival analysis.

RESULTS

Out of a total of 2261 consecutive UM patients, after excluding 4 children (<15 years) and 6 patients who were metastatic at presentation, we identified 272 AYA patients and matched 270 of them with 270 elder adult patients. Before PSM, the AYA patients had a higher incidence of primary iris melanoma (4.0% vs. 1.4%; p = 0.005), while the elder patients were more likely to have other neoplastic diseases at presentation (9% vs. 3.7%; p = 0.004). Ocular outcomes and local tumor control were similar in both groups. Cumulative metastasis incidence for the AYA and elder adult groups was 13% and 7.9% at 5 years and 19.7% and 12.7% at 10 years, respectively, which was not significantly different between the groups (p = 0.214). The OS was similar in the two groups (p = 0.602), with estimates in the AYA and elder adult groups of 95.5% and 96.6% at 5 years and 94.6% and 91.4% at 10 years, respectively. However, the relative survival (RS) estimation was worse in the AYA group than the elder group (p = 0.036).

CONCLUSION

While AYAs treated with PT for UM have similar ocular outcomes and present the same metastasis incidence and OS as elder adults, their RS is worse than that in elder adults, when compared with the population in general.

Iris melanocytic tumours in New Zealand/Aotearoa: presentation, management and outcome in a high UV exposure environment

BACKGROUND/OBJECTIVES

Iris melanoma, a rare intraocular malignancy, represents the smallest subgroup of uveal melanoma. This first, comprehensive study of iris melanocytic lesions in the high ultraviolet environment in New Zealand/ Aotearoa (NZ) examines diagnosis, management and outcomes.

SUBJECTS/METHODS

Retrospective study of iris melanocytic tumours referred to tertiary referral centres in Auckland, NZ, over 20 years (1999-2018). Data analysed include demographics, tumour characteristics, histology, genetic analyses, treatment modalities, recurrence, metastasis, 5-year and overall survival.

RESULTS

Cohort (N = 51) was predominantly NZ European (98.0%) with no indigenous Māori, or Pasifika. Median age at presentation was 58 years. Tumours involved a median of two clock hours of iris. The posterior tumour margin extended to the anterior chamber angle in 22 patients (45.8%). Management included initial observation 54.9%, iridectomy/excision biopsy 29.4%, irido-cyclectomy 7.8%, plaque radiotherapy 7.8%, proton beam radiotherapy 7.8%, and ultimately enucleation 17.6%. Histology was performed in 19 cases (37%) with 16 confirmed melanomas (84%). Mean follow-up 4.2 years with median visual acuity of 6/7.5 two years post intervention. Melanoma-related metastasis and mortality occurred in two cases with five-year melanoma-related mortality of 2.0%.

CONCLUSION

In a climate with high ultraviolet exposure iris melanocytic tumours occurred almost exclusively in NZ Europeans, however, the majority of cases were category T1, possibly reflecting early diagnosis in the NZ health system. Nonetheless, >50% underwent surgery or radiotherapy, often utilising more than one modality. A high index of suspicion and early referral of iris melanocytic lesions should be considered in regions with high UV exposure.