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Abstract A 73‐year‐old woman with a history of rheumatoid arthritis treated with methotrexate (MTX) for the last 10 years was referred to our hospital for a pancreatic tumor examination. Contrast‐enhanced abdominal computed tomography revealed a 20‐mm‐diameter hypovascular tumor in the pancreatic tail. A hypoechoic mass with heterogeneous internal echo was found on an endoscopic ultrasound (EUS). An EUS‐guided fine‐needle biopsy (EUS‐FNB) was performed with a 22‐gauge Franseen‐tip needle. Histologic examination of EUS‐FNB specimens from the pancreatic tumor revealed the proliferation of atypical spindle cells. Immunohistochemical staining for CD20 and Ki‐67 was positive in the atypical cells. Immunohistochemical staining for CD3 was partially positive in the atypical cells. Epstein–Barr virus‐encoded RNA in situ hybridization showed positive staining. MTX‐related lymphoproliferative disorder (MTX‐LPD) with Epstein‐Barr virus infection was diagnosed. MTX treatment was immediately discontinued, and treatment was initiated by a hematologist. However, her condition rapidly deteriorated, and she died of multiple organ failure 4 weeks after diagnosis. MTX‐LPD can complicate gastrointestinal lesions. However, most lesions are localized in the stomach and rarely complicate pancreatic lesions. MTX‐LPD is classified as an “iatrogenic” LPD. Therefore, immediate action, such as MTX discontinuation, is necessary. In conclusion, endoscopists should be aware that MTX‐LPD lesions can occur in the pancreas and gastrointestinal tract. Moreover, EUS‐FNB can be useful in the diagnosis of this rare pancreatic tumor.

Wireless communications, encompassing mobile communications, satellite communications, wireless local area networks (LANs), and fixed wireless systems, play a major role in communication networks. In preparation for the World Radiocommunication Conference 2023 (WRC-23) that was held in November 2023, the International Telecommunication Union - Radiocommunication Sector (ITU-R), a de jure standards organization, conducted studies and discussions broader than those limited to Beyond 5thgeneration mobile communication system (5G) and 6G. The 3rd Generation Partnership Project (3GPP), a private standardization organization, has also started to study specifications after Release 18 under the name "5G-Advanced," as a further evolved version of 5G. The IEEE 802.11 Working Group (WG), a WG of the Standards Association under the Institute of Electrical and Electronics Engineers (IEEE), is studying next-generation wireless LANs. This article introduces these standardization efforts as well as the NTT Group's activities for standardization of satellite communications, fixed wireless communications, and radio-wave propagation. [ABSTRACT FROM AUTHOR]