Pathology A 56 year old Chronic smoker, mass in bronchus resected. Most useful immunohistochemical marker to make a proper diagnosis would be A Cytokeratin B Vimentin C Epithelial membrane cadherin D Leucocyte common antigen 💡 Explanation A 56 year old Chronic smoker, mass in bronchus resected. Most useful immunohistochemical marker to make a proper diagnosis would be ✓ Correct Answer: A. Cytokeratin