TTF1 and adenocarcinoma: Haematoxylin and eosin (HE) staining of the primary surgically resected tumour sample revealed typical adenocarcinoma histology with positive IHC markers including Napsin A, cytokeratin 7 (CK7), thyroid transcription factor‐1 (TTF‐1) and ALK (Ventana, Figure 1B).