Chromosomal aberrations by 4-color fluorescence in situ hybridization not detected in Spitz nevi of older individuals.

OBJECTIVE To investigate whether Spitz nevi with typical histopathological features in older patients demonstrate chromosomal aberrations by 4-color fluorescence in situ hybridization (FISH). DESIGN Retrospective medical record review, with prospective masked histopathological and cytogenetic analyses. SETTING University-affiliated dermatology and dermatopathology setting. PATIENTS Twenty-five patients 50 years or older with melanocytic nevi showing histopathological features typical of Spitz nevi. MAIN OUTCOME MEASURES Three dermatopathologists masked to the patients' ages reviewed histopathological sections of melanocytic lesions for features typical of Spitz nevi. FISH was performed on samples with typical histopathological features by a 4-color FISH probe set used for the evaluation of malignant melanocytic neoplasms. RESULTS None of the study cases showing histopathological features typical of Spitz nevi had detectable chromosomal abnormalities by FISH. CONCLUSIONS Spitz nevi in older patients demonstrate molecular features similar to those of Spitz nevi in younger age groups. The findings of normal karyotypes in combination with typical histopathological features are reassuring of Spitz nevus diagnoses in older patients and suggest no correlation of increased malignant potential with advanced age per se.