Lump on my left buttock

I have a lump on my left buttock, which at first the doctors initially thought was a pilonidal cyst. However, 3 days ago I had my ultrasound and the reports say that it is solid with no puss inside and it doesnt look suspicious. The reports also say that at this time it is not determined what it is. My doctor has referred me to a surgeon now. I have a couple of questions

1) Is it normal to have solid lumps under the skin?

2) Has anyone else has this experience before. 

I have read some stuff online where a lump was diagnosed for a pilonidal cyst and the cyst was never taken out and years later it turned out to be cancerous. 

I'd appreciate if people can share their experiences. 

Thanks and God bless!