This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anal Malignancy, Subject name: Surgery
Commonest type of Anal canal Ca is : 
Select and explain. 
A. Sq. cell Ca, B. Adeno Ca, C. Adenoacanthoma, D. Papillary type
A: Sq. cell Ca
Answer: A: Sq. cell Ca 
Explanation: Ans. is 'a' ie Squamous cell Ca Mainly 3 types of malignant neoplasm are seen in anal canalSquamous cell Ca (MC)Basal cell Ca (IInd me)MelanomaRememberMC type of rectal & colon Ca - Adenocarcinoma*.