Brief ReportMultiple Basal Cell Carcinomas of the Scalp After Radiotherapy: Genomic Study in a Case With Latency Period Over 80 YearsCardoso, José Carlos MD*; Ribeiro, Ilda Patrícia PhD†,‡; Caramelo, Francisco PhD§; Tellechea, Oscar PhD*; Barbosa de Melo, Joana PhD†,‡,¶; Marques Carreira, Isabel PhD†,‡,¶ Author Information *Dermatology Department, Coimbra Hospital and University Centre, Coimbra, Portugal; †Cytogenetics and Genomics Laboratory, Faculty of Medicine, University of Coimbra, Coimbra, Portugal; ‡iCBR-CIMAGO—Center of Investigation on Environment, Genetics and Oncobiology—Faculty of Medicine, University of Coimbra, Coimbra, Portugal; §Laboratory of Biostatistics and Medical Informatics, IBILI—Faculty of Medicine, University of Coimbra, Coimbra, Portugal; and ¶CNC, IBILI, Group of Aging and Brain Diseases, Advanced Diagnosis and Biomarkers, Coimbra, Portugal. Correspondence: José Carlos Cardoso, MD, Dermatology Deparment, Coimbra Hospital and University Centre, Praceta Mota Pinto, 3000-075 Coimbra, Portugal (e-mail: [email protected]). J. C. Cardoso and I. P. Ribeiro contributed equally to this work. I. P. Ribeiro is a recipient of a fellowship from HEALTHY AGING 2020 (CENTRO-01-0145-FEDER-000012). The authors declare no conflicts of interest. The American Journal of Dermatopathology: June 2021 - Volume 43 - Issue 6 - p 438-442 doi: 10.1097/DAD.0000000000001801 Buy Metrics Abstract Basal cell carcinoma (BCC) has been linked mostly to ultraviolet radiation exposure, but ionizing radiation has also been implicated in the genesis of a subset of BCCs occurring after radiotherapy. We present a 93-year-old woman with 4 BCCs of the scalp after radiotherapy for tinea capitis, diagnosed after a latency period of over 80 years. The largest lesion was located on the right temporal region and corresponded to a BCC of mixed type, with nodular, infiltrative, and micronodular components. We performed genomic study with array comparative genomic hybridization in samples from each BCC, which revealed more imbalances in the largest lesion than in the remaining ones, correlating with its higher histological complexity. Furthermore, this was the only lesion presenting loss at 2p22.3, where is mapped the BIRC6 gene associated with regulation of apoptosis, and loss at 16q24.3, where is mapped FANCA gene, responsible for DNA repair and maintenance of chromosome stability. Despite these differences, there were aberrations shared by all tumor samples, suggesting a common genetic signature. Our report describes, to the best of our knowledge, the longest latency period between exposure to radiotherapy and the diagnosis of BCC. The genomic study showed imbalances common to all tumor samples but also differences that could explain their heterogeneity in terms of histological subtype and biological potential. In addition, these differences could also be a consequence of different times in the evolution of the lesions at the moment of presentation, thus having a diverse combination of accumulated genomic imbalances. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.