Track: Clinical Studies

Abstract:

Background: Ambiguous melanocytic neoplasms in the pediatric population pose a diagnostic quandary. Ancillary tests such as the 23-gene expression profile (23-GEP) are intended to augment H&E evaluation of these ambiguous melanocytic neoplasms. While developed and validated in patients of all ages, the 23-GEP has not been evaluated specifically in the pediatric population. Here, we describe the performance of 23-GEP in patients <18 years of age.

Methods: Melanocytic neoplasms from patients <18 years of age with 23-GEP results were obtained from 6 sites. All neoplasms underwent digital histopathological review by three expert dermatopathologists. Neoplasms with conflicting diagnoses (i.e. both a benign and malignant designation) were excluded from analyses. Neoplasms achieving a majority designation were included in the performance calculations (n=201). Accuracy metrics were calculated with 23-GEP intermediate results reported as a separate metric.

Results: One hundred and eighty-three nevi and 18 melanomas were included in this cohort. In pediatric patients, the 23-GEP test demonstrated 92.3% (95% CI, 64.0–99.8%) sensitivity, 86.1% (79.8–91.0%) specificity, 86.9% (76.0–91.7%) positive predictive value, and 91.8% (69.9–99.8%) negative predictive value; 11.4% of neoplasms received an intermediate result. These metrics do not deviate significantly from previously published studies using all-aged patients.

Conclusions: The 23-GEP test performance in a pediatric population was similar to that seen in all-aged cohorts. These data support use of 23-GEP as an ancillary test that can be integrated with clinical and histopathologic information to guide final diagnosis of melanocytic neoplasms in pediatric patients.

Drazen Jukic

Affiliation

Refine Results

(207) 23-GEP accurately distinguishes between melanocytic nevi and melanoma in pediatric melanocytic neoplasms