[Angioimmunoblastic T-cell lymphoma after immune checkpoint inhibitor-combined chemotherapy for lung cancer].

A 68-year-old male patient with lung adenocarcinoma, who was treated with chemotherapy and immune checkpoint inhibitors (ICIs), developed lymphadenopathy during treatment. His para-aortic lymph nodes increased to 2.0 cm in diameter. Both inguinal lymph nodes were 1.5 cm in diameter, and multiple hepatic masses appeared. After the ICI readministration, both inguinal lymph nodes increased to 2.0 cm in diameter, but the para-aortic lymph nodes and hepatic masses remained. Angioimmunoblastic T-cell lymphoma (AITL) diagnosis was established after the right inguinal lymph node biopsy, which was accompanied by an infiltration of Epstein-Barr virus (EBV)-encoded small ribonucleic acid-positive B-cells. After the ICI discontinuation, the inguinal lymph nodes decreased to 1.5 cm in diameter, but the para-aortic lymph nodes remained, and hepatic masses increased. Hepatic lesions were possibly lung cancer metastasis. The ICI administration and EBV reactivation were potentially associated with AITL development in the present case. The natural shrinkage of lymphoma after the ICI cessation implied the immunological mechanism like that of the methotrexate-related lymphoproliferative disease.