Small Choroidal Melanoma: Correlation of Growth Rate with Pathology

Abstract

<b><i>Purpose:</i></b> The aim of the study was to evaluate equivalence of growth rate and pathologic confirmation in small choroidal melanoma (SCM). <b><i>Design:</i></b> This study is a case series. <b><i>Subjects, Participants, and Controls:</i></b> A total of 61 patients with a choroidal melanocytic tumor of size 5.0–16.0 mm in the largest basal diameter and 1.0–2.5 mm in thickness were classified into the pathology-confirmed group (<i>n</i> = 19), growth-confirmed group (<i>n</i> = 30), and with combined observations (<i>n</i> = 12). <b><i>Methods:</i></b> Distribution of clinical variables (age, gender, laterality, tumor dimensions, tumor location, and presence of orange pigment, subretinal fluid, drusen, and retinal pigment epithelial [RPE] atrophy) between the groups was analyzed. Patient and disease characteristics were summarized as the median and interquartile range for continuous variables and the frequency and percentage for categorical variables. Comparisons were made using the Wilcoxon rank sum test for continuous variables and either Fisher’s exact test or the χ<sup>2</sup> test for categorical variables with a <i>p</i> value threshold of 0.05 for statistical significance. Growth rate (change in basal dimension/12 months) diagnostic of SCM was quantified. <b><i>Main Outcome Measures:</i></b> The primary aim of this study was to test the hypothesis that “growth” was diagnostic of SCM with the secondary aim of quantifying the malignant “growth rate” (growth rate of SCM). <b><i>Results:</i></b> The clinical characteristics among all 3 groups were similar except more patients with symptoms (68 vs. 20 vs. 42%, <i>p</i> = 0.004) and juxtapapillary location (<i>p</i> = 0.03) were in the pathology group than in the growth-confirmed group. Those in the combined and growth-confirmed groups had more patients with drusen (11 vs. 60 vs. 50%, <i>p</i> = 0.003) and RPE atrophy (11 vs. 23 vs. 67%, <i>p</i> = 0.003), respectively, than in the pathology group. The median time to detect growth was 9 months (range 3–26 months). The mean growth rate in basal dimension was 1.8 mm/12 months (range, 0.0–7.4 mm; [95% CI: 1.32–2.28]). <b><i>Conclusions and Relevance:</i></b> Choroidal melanocytic lesions exhibiting a defined growth rate can be clinically diagnosed as SCM without a need for biopsy.

Predicting Malignant Transformation of Choroidal Nevi Using Machine Learning

“…Early detection and treatment of UM is crucial as metastasis events may occur early, and effective treatment can prevent its spread. 45 , 46 Despite the availability of effective treatments for the primary tumor, more than 50% of UM patients develop metastatic disease suggesting that UM may metastasize prior to the time of treatment. 45 , 47 Consequently, there is a need for identifying and treating small UM to minimize the number of melanocytic choroidal tumors that are observed and subsequently grow during the observation period.…”

Malignant Transformation of a Choroidal Nevus after 19 Years of Observation Followed by Rapid Progression of the Choroidal Melanoma

“…2 Malignant transformation is characterized by a more rapid and consistent progression. Individual growth rates of melanoma are variable and dependent on specific tumor characteristics, but studies have shown an average growth of 0.96 to 1.8 mm/year in LBD 3,4 and 1.12 mm/ year in thickness. 3 Treatment within a few weeks is recommended because growth over such a short period is not believed to be sufficient to require radiation dose alteration while not increasing the risk of metastasis significantly.…”