01 June 2024
: Case report
Simultaneous Acquisition of T790M Mutation and SCLC Transformation during Targeted Therapy in EGFR-Mutated Lung Adenocarcinoma: A Rare Case Report
Unusual clinical course
Tatsuya Yazaki12AEF*, Masanobu Kimoto1E, Ayumi Minagawa1E, Takashi Maruno1E, Miwa Yamanaka12E, Kei Sonehara2EF, Mineyuki Hama1E, Toshitsugu Nakamura3E, Shintaro Kanda4E, Masayuki Hanaoka2E, Tsutomu Hachiya1EFDOI: 10.12659/AJCR.943466
Am J Case Rep 2024; 25:e943466
Figure 2. Images of Histopathology and Immunohistochemistry in each. A(i) Pneumonectomy. Hematoxylin-eosin (HE) staining from a right pneumonectomy performed in May 2012. Histology showing tubular structures indicative of adenocarcinoma was observed, but small cell lung carcinoma was not identified. (magnification objective ×40). A(ii) Chest wall tumorectomy. HE staining of resection from the right 6th and 7th rib in March 2019. Histology shows 2 structures; a dense fenestrated structure on one side and a tubular arrangement on the other (magnification objective ×20). A dense fenestrated structure zoom-in indicates that individual cells have irregularly round, swollen nuclei with distinct nucleoli and mitosis (magnification objective ×40). (B) Pneumonectomy. Immunostaining was performed on the solid and acinar components of the adenocarcinoma. TTF-1 and CD56 exhibited positive nuclear staining on the tumor cells. Chromogranin A and synaptophysin expression were negative following a right pneumonectomy in May 2012 (magnification objective ×40). (C) Chest wall tumorectomy. On a resection from the right 6th and 7th rib in March 2019 (magnification objective ×20), the tubular arrangement was positive for TTF-1 nuclear staining, whereas the fenestrated structure was positive for TTF-1, CD56, Chromogranin A, and synaptophysin.