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: ENT
A 65 year old male with a history of smoking and alcohol abuse complains of poor appetite and difficulty swallowing both solid and liquid foods over the course of the last 4 months. He has lost 10 Kg and occasionally vomits blood. A mass is detected in his esophagus and is subsequently biopsied. What is the most likely histological appearance of the biopsy? 
Select and explain. 
A. Glandular epithelium associated with desmoplasia, B. Malignant tumor of mesenchymal origin, C. Squamous cell morphology, D. Tumor derived from all three germ layers
C: Squamous cell morphology
Answer: C: Squamous cell morphology 
Explanation: The most common esophageal cancer is squamous cell in origin. The esophageal mucosa consists of stratified, nonkeratinized, squamous epithelium. Smoking and alcohol increase the risk for the development of esophageal carcinoma. Suspect cancer when there are signs like rapid weight loss in a sho period of time and symptoms such as dysphasia, hematemesis, and anorexia.