Large subcutaneous puss filled unkown

My brother has had an extremely large not on his back for years. I popped it and out shot about 2 tablespoons of rancid smelling yellow puss that even shot up to the ceiling? Matter of fact it smelt so bad we had to leave the house and I had to shower afterwards to get rid of the smell.

[chellybeans]

that is a cyst. it is a bad idea to pop them, usually they need to be either drained, excised, or injected to kepp them from either refilling or becoming infected.

look up sebaceous cyst for more on this.

and yes, they stink horridly and the pus can look like foul cottage cheese and worse. not a fun thing at all, but quite common.