This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which of the following is the best marker to distinguish Thymoma from lymphoma? 
Select and explain. 
A. CD19, B. Cytokeratin, C. CD79a, D. Laminin
B: Cytokeratin
Answer: B: Cytokeratin 
Explanation: Both thymoma and Lymphoma are common mediastinal tumors. But Thymoma has both Lymphocytic & Epithelial Component. Hence "Cytokeratin" which is a epithelial cell marker is best to distinguish it from Lymphoma.