TTF1 and adenocarcinoma: Our findings indicate that bulky tumors were associated with older age, smoking history, squamous-cell histology, TTF1 negativity, and elevated CRP, whereas diffusely metastatic disease was more common in younger patients, adenocarcinoma histology, TTF1 positivity, poorly differentiated tumors, elevated LDH, and oncogenic driver mutations (EGFR, ALK).