A 67 year male smoker presents with haemoptysis and cough. Bronchoscopic biopsy revealed undifferentiated tumour. The immunohistochemical marker that can be most helpful is-
High-Yield Explanation
Ans is 'c' i.e., Cytokeratin o Mass in bronchus in a old chronic smoker suggest bronchogenic carcinoma. The marker of carcinoma, on immunohistochemistry, is cytokeratin.