question: 33 yr old female, noticed a lump at base of skull, back of neck one year ago. At that time it was about the size of a grape and kind of lumpy. Now, it is hard as a rock and the size of a golf ball. I notice it more when head is tilted up. I get severe headaches, 2weeks straight now. Feels like my head and neck is FULL , pressure. I am concerned because I was told it could be a lipoma about a year ago and to keep an eye on it. But, I am worried because it is getting larger and tender. My neck also feels stiff. Is this something I should be concerned about?