I Have Two Lumps On The Back Of My Head

I have two lumps on the back of my head and have had them for about 10yrs. I just noticed today they are getting bigger. They are squishy. But they do not hurt. My mother has a couple also and her Dr said they were pockets of oil. My brother also has them. I have never asked a Dr about them since my mom told me what her Dr said. The are a nuisance more than anything. Should I go to the Dr?