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Purpose: Small choroidal melanocytic lesions have a low rate of metastasis and can be reasonably managed with surveillance until they demonstrate evidence of growth or clinical risk factors for melanoma. However, even choroidal nevi are not stationary, with many exhibiting slow growth over time. We sought to quantify the growth rates of indeterminate choroidal lesions that were initially observed prior to a clinical diagnosis of melanoma., Methods: A single-center retrospective study was performed of patients diagnosed with choroidal melanoma based upon clinical characteristics who were initially followed for indeterminate lesions over at least 6 months. Subjects were included if they had a minimum of two B-scan ultrasound measurements prior to the visit at which melanoma was diagnosed. Demographic and tumor characteristics were collected from the medical record. Growth rates were calculated as the change in lesion thickness in mm per month and were recorded at 6-month intervals; ultrasound measurements less than 1 month apart were excluded. The characteristics of indeterminate lesions with faster versus slower growth rates prior to melanoma diagnosis were compared., Results: Fifty-four patients met inclusion criteria. The mean age at melanoma diagnosis was 67.4 years, and 53.7% were female. Subjects had a median of four B-scan ultrasound measurements prior to melanoma diagnosis (range 2-19) and were followed for a median of 40.6 months (range 9.9-138.0 months). The mean lesion thickness was 1.4 mm (range 0.5-2.2 mm) at presentation, and increased to 2.3 mm (range 1.5-5.7 mm) at melanoma diagnosis. The mean growth rate did not exceed 0.021 mm/month (95% CI: 0.004-0.039; equivalent to 0.25 mm/year) for indeterminate lesions, but increased to 0.057 mm/month (95% CI: 0.043-0.071 mm/month; equivalent to 0.68 mm/year) at the time of melanoma diagnosis. Rapidly growing lesions had a greater tumor thickness and shorter duration of observation at the time of melanoma diagnosis., Conclusion: For most indeterminate choroidal lesions eventually diagnosed as melanoma, the lesion thickness was relatively stable for a period of time, then rose significantly between the penultimate visit and the final visit. These findings confirm the recommendation for continued monitoring of suspicious choroidal lesions, as the growth rate may accelerate just prior to melanoma diagnosis. Lesions with a mean growth rate of up to 0.25 mm/year were observed, whereas lesions clinically determined to have transformed into melanoma demonstrated a mean growth rate of 0.68 mm/year. These values provide a baseline for future studies and potential therapies directed at stabilizing or reducing the growth of indeterminate choroidal lesions or small choroidal melanomas. Limitations of this study include its retrospective nature and reliance on clinical diagnostic criteria., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The diagnosis of iris melanoma can be difficult, with no established diagnostic criteria currently available. Careful monitoring of patients with suspicious iris lesions is one approach to managing these tumors. We determined the risk of malignant transformation and melanoma-related mortality in patients under observation to evaluate the validity of this management approach., Methods: This was a retrospective chart review of patients with suspicious iris lesions diagnosed at Massachusetts Eye and Ear Infirmary (MEE) between 1975 and 2014. All patients with an initial diagnosis of suspicious iris lesion followed and/or treated after malignant transformation at the MEE in this 39-year period were included in the cohort. Rates of malignant transformation and melanoma-related mortality were calculated. Treatment outcomes after proton beam irradiation were evaluated in patients who developed iris melanomas during observation., Results: Two hundred thirty-four patients had a diagnosis of suspicious iris lesion (median follow-up, 5.8 years). Malignant transformation occurred in 16 (6.8%) patients with suspicious lesions during the observation period (median follow-up, 9.9 years). All patients diagnosed with iris melanomas were treated with proton beam irradiation (PBI). Complications after treatment included cataract (18.8%), secondary glaucoma (6.3%), and neovascular glaucoma (12.5%). Two of 16 patients (12.5%) who developed iris melanomas died of metastatic melanoma 32.6 months and 10 years after treatment with PBI. Both cases had been followed regularly to monitor for malignant transformation of their suspicious lesions (8.2 years and 3.2 years before melanoma diagnosis, respectively)., Conclusions: These data suggest that suspicious iris lesions have low malignant potential, and a conservative approach to the management of these lesions is appropriate. Survival does not appear to be compromised with an observational approach, and there is potential for preservation of good visual function because vision-threatening treatments can be avoided.