<prompt> A 56 year old chronic smoker, mass in bronchus resected. What is the possible marker:CytokeratinVimentinEpithelial membrane CadherinLeukocyte  <response>: Ans. a CytokeratinRef: Robbins 9thpg 715-717Chronic smoker with mass in bronchus suggests a diagnosis of small ell Ca and squamous cell ca.Diagnosis for squamous cell Ca is Keratinization squamous pearls Q on light microscopy, diagnosed by cytokeratin andor Intercellular bridges Q on electron microscopy is diagnostic. 