Fig. 2From: ALK-rearranged lung squamous cell carcinoma responding to alectinib: a case report and review of the literatureTransbronchial lung biopsy specimen from a mediastinal lymph node. a Hematoxylin and eosin staining revealed undifferentiated cancer cells with a mild tendency of cornification (arrows). Immunohistochemical staining revealed that the tumor cells were negative for (b) thyroid transcription factor-1, but positive for (c) p40 and (d) cytokeratin 5/6Back to article page