Multi-institutional retrospective study demonstrates benign behavior and distinct histopathology of SPARK nevi in 74 patients, indicating favorable outcomes despite mimicking melanoma.
Key Points
To characterize the clinical, histopathologic, and immunohistochemical profile of SPARK nevi and define their biological behavior.
Retrospective multi-institutional review of 74 SPARK nevi collected across six academic centers using standardized diagnostic criteria combining Spitzoid cytology with Clark-type architecture.
Evaluated clinical demographics, lesion morphology, immunohistochemical markers (PRAME, p16, MKI67), and longitudinal clinical follow-up data (median 18 months).
Lesions occurred predominantly in females (76%) with a mean age of 32.4 years, showing small size (mean diameter 5.8 mm), compound architecture (70%), and infrequent Kamino bodies (9%).
Immunohistochemistry demonstrated negative PRAME expression, retained p16 expression, and low MKI67 proliferation indices in evaluated cases.
Clinical follow-up available in 93% of patients revealed one local recurrence, two metachronous SPARK nevi, and zero disease-related deaths.