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: Pathology
Ectopic ACTH production is seen in 
Select and explain. 
A. Small cell carcinoma is lung, B. Anaplastic carcinoma of lung, C. Squamous cell carcinoma of lung, D. Adenocarcinoma of cerebellum
A: Small cell carcinoma is lung
Answer: A: Small cell carcinoma is lung 
Explanation: Ans. is 'a' i.e, Small cell carcinoma of lung Ectopic ACTH is produced by Small cell carcinoma of lung (most common) Carcinoid tumors Medullary Carcinoma of thyroid Islet cell tumors of pancrease