Opsoclonus-myoclonus syndrome associated with neuroblastoma (OMS-NB) is a refractory paraneoplastic syndrome which often remain neurological sequelae, and detailed pathogenesis has remained elusive. We encountered a pediatric patient with OMS-NB treated by immunosuppressed therapy who showed anti-glutamate receptor δ2 antibody and increased B-cells in cerebrospinal fluid (CSF), and multiple lymphoid follicles containing abundant B-cells in tumor tissue. Unbiased B-cell receptor repertoire analysis revealed identical B-cell clone was identified as the dominant clone in both CSF and tumor tissue. These identical B-cell clone may contribute to the pathogenesis of OMS-NB. Our results could facilitate the establishment of pathogenesis-based treatment strategies for OMS-NB.

High-dose methotrexate-induced acral erythema in two pediatric patients with acute lymphoblastic leukemia: a 17 pediatric case series of methotrexate induced acral erythemaKazuhiro Noguchi,1 Ryosei Nishimura,1* Yasuhiro Ikawa,1Shintaro Mase,1 Toshihiro Fujiki,1Rie Kuroda,1 Raita Araki,1 Hideaki Maeba,1 Akihiro Yachie1 and Taizo Wada1