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: Gynaecology & Obstetrics
You are awaiting for the histopathology repo of sample taken from a suspected case of Ca endometrium. Which of the following histological pattern has the WORST prognosis? 
Select and explain. 
A. Adenoacanthoma, B. Adenocarcinoma, C. Papillary Carcinoma, D. Clear cell Carcinoma
D: Clear cell Carcinoma
Answer: D: Clear cell Carcinoma 
Explanation: Adenocarcinoma is the commonest type and is seen in about 80 - 90% of the case. Adenoacanthoma has got the least malignant potential and highest survival rate. Clear cell Ca is the most malignant and has got the worst prognosis. Ref: Shaw's textbook of gynaecology,edition 12 , Page -304.