<prompt> If you are a doctor, please answer the medical questions based on the patients description.I have had a big knot behind my ear for almost a year now. It is in the mastoid process bone area. It worries me because it is hard like a bone, but swollen like a cyst. It worries me because I have never had any ear issues, but this occasionally throbs. I have also now noticed a big cyst located in the back of my neck that is also seemingly permanent. I thought it was simply a muscular knot like those caused after exercising and can easily be massaged out, but it seems to also be a permanent thing. this one, however, is not solid, more like a marble in my neck. Any idea what may be wrong with me?  <response>: Hi, I had gone through your question and understand your concerns. As per your information, its located at mastoid process, there is a possibility of a condition called as mastitis infection in the mastoid bone behind the ear. For my patients I suggest putting 1 to 2 Chat Doctor. Have you ever experienced fever, headache, irritability or hearing loss? Also, there could be a possibility of a cyst formation caused by blocked sebaceous glands also called sebaceous cysts. Heating pads and warm compresses can help 