Ive noticed mushrooms growing right near the top of my spruce tree?
You should be concerned: mushrooms grow on rotting organic matter which means your spruce must be experiencing the results of some pathogen rotting your tree. By the time you are seeing some mushrooms, the rot is likely pretty extensive. You can inhibit the growth of the fungal pathogens (neem oil, among other treatments) but you will likely only halt the progress of the pathogen and never fully cure your tree. Can you get a look at where the mushrooms are growing and see the state of the tree? It may be in your best interests to remove the tree to halt the spread to other trees in your property.