There are a few species of wood decay fungi in maple (based on the few leaves I see, this looks like a maple) and these species will enter through open wounds/cracks. Often, these pathogens remain internal and it is not until much later, when their fruiting bodies appear on the outside of the tree, that they are detected. The external fruiting bodies will fade when the environmental conditions become less favorable. 

The best thing I can suggest is to call a certified arborist to come out, take a look at the tree and the fungal fruiting body in person and do a risk assessment if you are concerned about the tree. They will have the tools to probe the tree and see is there is any extensive rot. You can find a local certified arborist using this site: https://www.treesaregood.org/findanarborist/arboristsearch

Due to the diversity of mushrooms, along with the fact that many look alike, and varying toxicity of mushrooms, we’re unable to identify mushrooms or indicate whether or not they are edible - especially based on just photos. Getting it wrong could have serious, if not deadly, consequences.

Please read the following article from a colleague: 

Identifying mushrooms - There is more to it than you might realize: http://msue.anr.msu.edu/news/identifying_mushrooms_there_is_more_to_it_than_you_might_realize

Here are a few additional resources that may be helpful:

• Midwest American Mycological Information (MAMI): http://www.midwestmycology.org/Index.html

• Michigan Mushroom Hunters Club (MMHC): https://michiganmushroomhunters.org/

• North American Mycological Association (NAMA): http://www.namyco.org/