Clinical and Laboratory ObservationsGenetic Profile and Microsatellite Instability in a Case of Secondary Esophageal Squamous Cell Carcinoma 12 Years After Allogeneic Hematopoietic Stem Cell Transplantation for Aplastic AnemiaAkiyama, Masaharu MD, PhD*; Yamaoka, Masayoshi MD*; Ohyama, Wataru MD*; Yokoi, Kentaro MD, PhD*; Ashizuka, Shuichi MD, PhD†; Aizawa, Daisuke MD, PhD‡; Ikegami, Masahiro MD, PhD‡; Suzuki, Hideaki MD, PhD§; Ozaki, Koji BSc∥; Ida, Hiroyuki MD, PhD*; Yuza, Yuki MD, PhD*Author Information Departments of *Pediatrics †Pediatric Surgery ‡Pathology §Anatomy ∥Division of Molecular Genetics, Research Center for Medical Science, Core Research Facilities for Basic Science, The Jikei University School of Medicine, Tokyo, Japan The study was supported by The Jikei University Research Fund (to M.A.). The authors declare no conflict of interest. Reprints: Masaharu Akiyama, MD, PhD, Department of Pediatrics, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan (e-mail: firstname.lastname@example.org). Received August 13, 2018 Accepted October 14, 2018 Journal of Pediatric Hematology/Oncology: May 2020 - Volume 42 - Issue 4 - p 302-306 doi: 10.1097/MPH.0000000000001355 Buy SDC Metrics Abstract We report on a 16-year-old Japanese boy in whom an esophageal squamous cell carcinoma (ESCC) developed 12 years after allogeneic hematopoietic stem cell transplantation was performed for aplastic anemia. A high frequency of microsatellite instability was detected in samples of ESCC. Moreover, the detection of pathogenic variants, including single nucleotide substitution of TP53 (c.346C>T) and BRCA2 (c.6952C>T) and splicing of KDM6A (c.1194+2T>G), suggest that the development of ESCC in the patient was triggered by impairment of checkpoint and repair for DNA damage and epigenetic modification through accumulation of gene mutations induced by chronic graft-versus-host disease and prolonged administration of tacrolimus. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.