Lung cancer is a rare event in the pediatric and adolescent population. To date, only a few case reports and small case series have been published, and little is known about the risk factors associated with this entity in children and adolescents. We describe a case of adenocarcinoma in situ in a 15-year-old adolescent girl with previous surgical treatment for malignant melanoma. We provide a detailed genomic characterization of this neoplasm by comparative genomic hybridization, genome-wide single-nucleotide polymorphism array, and fluorescence in situ hybridization analyses. We identify chromosomal regions with copy number changes and correlate the corresponding genes within these regions with the available literature in the area.