My husband is 6'10". He is 33. He is healthy except we are concerned with a softball size mass that has shown up at his tailbone. He is an equip opera?

Pilonidal Cyst. This may very well be a common abnormality called a pilonidal cyst. This can require surgery to drain it or to remove it. You may be best helped by getting him to your family doctor today.
Pilonidal "cyst"? Get it seen in any case. A big man sitting on his tailbone on a bumpy job is a setup for this, even if he's not super-hairy. And if it is not a pilonidal "cyst", it needs to be diagnosed in any case.