Which kind of tumor grows slowly and is surrounded by membranes that prevent it from spreading from the original site?

The tumor which grows slowly and is surrounded by membranes that prevent it from spreading from the original site is benign tumor

Explanation:

 Benign tumor is normally surrounded by membrane which will be identified by the doctors due to their protective sac. They are abnormal growths found in the body. They are normally not malignant and doesn’t spread to any other parts.

It is normally found as a mass of tissue in any part of the body which can be found as a lump. It can be removed safely by operating it. Normally in our body cells grow and then die and are discarded. In that place new cells are formed. But unfortunately in some cases these dead cells accumulate to form this lump known as benign.

the answer is anaerobic activities