Fig. 2
Histopathological findings. a An analysis of computed tomography-guided needle biopsy specimens did not lead to a definitive diagnosis due to severe tissue crushing (Hematoxylin and eosin staining). b The endobronchial ultrasound-guided transbronchial cryobiopsy specimens presented minimal crushing, and proliferating tumor cells with chromatin-enriched micronuclei were identified that formed scattered small foci against a background of extensive fibrous connective tissue with hyaline changes (Hematoxylin and eosin staining). c Immunohistochemical staining was positive for HNF4α, which is a finding suggestive of adenocarcinoma of gastrointestinal origin