This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
All are precancerous lesions for carcinoma of esophagus except 
Select and explain. 
A. Achalasia, B. Paterson Kelly syndrome, C. Zenker Diveiculum, D. Ectodermal dysplasia
C: Zenker Diveiculum
Answer: C: Zenker Diveiculum 
Explanation: Refer Robbins page no Pg 758-9 A Zenker's diveiculum, more formally known as a hypopharyngeal diveiculum, is a pouch that can form at the junction of the hypopharynx (lower pa of the throat) and the esophagus, an area known as Killian's Triangle