title: Spontaneous remission of 2-chlorodeoxyadenosine (2-CdA)-related secondary myelodysplastic syndrome in a patient with refractory Langerhans cell histiocytosis.
abstract: Langerhans cell histiocytosis (LCH) is sometimes resistant to conventional chemotherapies, and treatment with 2-chlorodeoxyadenosine (2-CdA) is gaining importance as a salvage treatment for refractory or recurrent LCH. Secondary malignancies such as acute myelogenous leukemia and myelodysplastic syndrome (MDS) due to 2-CdA have recently been reported. However, there have been no reports to date of cases of 2-CdA-related secondary MDS in which spontaneous remission was achieved. Here, we report the case of a 1-year-old boy with an occipital tumor who was diagnosed with LCH by biopsy and underwent chemotherapy. However, the disease relapsed and became refractory to chemotherapy. He received 2-CdA treatment, which was effective. However 6 months after the start of treatment, he developed MDS with chromosomal abnormality of 7q-. After 1-year observation without any intervention, his hematological findings had returned to normal, and the chromosomal abnormality had also disappeared. To our knowledge, this is the first report of 2-CdA-related MDS with spontaneous hematological remission.
authors.affiliation: Department of Pediatrics, Sapporo Hokuyu Hospital, Higashi-Sapporo 6-6, Shiroishiku, Sapporo, Japan. d-suzuki@chashu.org
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Ryoji
authors.initials: R
authors.lastname: Kobayashi
authors.forename: Hirozumi
authors.initials: H
authors.lastname: Sano
authors.forename: Kenji
authors.initials: K
authors.lastname: Kishimoto
authors.forename: Kazue
authors.initials: K
authors.lastname: Yasuda
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Nagashima
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D017338:Cladribine / Q000009:adverse effects* / Q000627:therapeutic use; D018380:Hematopoietic Stem Cell Transplantation; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D009190:Myelodysplastic Syndromes / Q000139:chemically induced* / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy; D012075:Remission, Spontaneous
chemical_list: D000970:Antineoplastic Agents; D017338:Cladribine