TY - JOUR T1 - Granulation Tissue-induced Pseudo-relapse During Nivolumab Treatment in Advanced Non-small Cell Lung Cancer JF - In Vivo JO - In Vivo SP - 2113 LP - 2115 DO - 10.21873/invivo.11711 VL - 33 IS - 6 AU - CHIHIRO ANDO AU - EIKI ICHIHARA AU - HIROHISA KANO AU - YOSHITAKA IWAMOTO AU - ATSUKO HIRABAE AU - TAKAMASA NAKASUKA AU - YOSHINOBU MAEDA AU - KATSUYUKI KIURA Y1 - 2019/11/01 UR - http://iv.iiarjournals.org/content/33/6/2113.abstract N2 - Atypical tumor responses such as pseudo-progression or hyper-progression sometimes occur during immune check point inhibitor therapy. Distinct from both responses, we experienced a case of non-small cell lung cancer (NSCLC) with a pseudo-relapse, in which development of granulation mimicked cancer relapse during nivolumab therapy. A male with advanced NSCLC started nivolumab as a second-line therapy. After 15 cycles of nivolumab with a complete response, tumor markers started increasing and positron-emission computed tomography indicated a hot spot in the sigmoid colon. Laparoscopic segmental sigmoid colon resection revealed granulation tissue without any relapse of malignant cells. The results showed that even if radiographical tumor progression is found during immune therapy, histological confirmation should be considered. ER -