This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Concepts, Subject name: Pathology
All are malignant tumors, except: 
Select and explain. 
A. Chloroma, B. Fibromatosis, C. Askin's tumor, D. Liposarcoma
B: Fibromatosis
Answer: B: Fibromatosis 
Explanation: * Fibromatosis are a group of fibroblastic proliferations. *They are locally aggressive, they do not metastasize.