The Japanese Society of Internal Medicine Acta Medica Okayama 0918-2918 60 19 2021 Nodal Peripheral T-cell Lymphoma with T Follicular Helper Phenotype Presenting as Chorea During Treatment: A Case Report and Literature Review 3155 3160 EN Wataru Kitamura Department of Hematology and Oncology, Okayama University Hospital Daisuke Ennishi Center for Comprehensive Genomic Medicine, Okayama University Hospital Ryoya Yukawa Department of Hematology and Oncology, Okayama University Hospital Ryo Sasaki Department of Neurology, Okayama University Hospital Chikamasa Yoshida Department of Hematology, Okayama City Hospital Hiroki Takasuka Department of Hematology and Oncology, Okayama University Hospital Hideaki Fujiwara Department of Hematology and Oncology, Okayama University Hospital Noboru Asada Department of Hematology and Oncology, Okayama University Hospital Hisakazu Nishimori Department of Hematology and Oncology, Okayama University Hospital Keiko Fujii Division of Clinical Laboratory, Okayama University Hospital Nobuharu Fujii Division of Blood Transfusion, Okayama University Hospital Ken-Ichi Matsuoka Department of Hematology and Oncology, Okayama University Hospital Koji Abe Department of Neurology, Okayama University Hospital Tadashi Yoshino Department of Pathology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences Yoshinobu Maeda Department of Hematology and Oncology, Okayama University Hospital A 72-year-old man presented with chorea while undergoing treatment for recurrence of nodal peripheral T-cell lymphoma with T follicular helper (TFH) phenotype. An examination by brain N-isopropyl-p-iodoamphetamine (I-123-IMP)-single photon emission computed tomography (SPECT) revealed no abnormalities other than a decreased cerebral blood flow (CBF) in the left striatum. After four courses of salvage chemotherapy, his clinical symptoms and asymmetric cerebral perfusion improved, suggesting that the decreased CBF had caused chorea. The significance of brain SPECT has not been fully clarified in patients with chorea-associated malignant lymphoma, warranting further investigations. Brain SPECT is an alternative approach to identify abnormalities in such patients. No potential conflict of interest relevant to this article was reported.