More information is required to provide appropriate help…
- what is it housed in and what substrate is used;
- how old is the snake and how long is it;
- a full size photo that shows which part of the body the lump is located;
- when it was last fed, with what and how;
- how often is it fed;
- when it last defecated;
- are any of the furnishing or other possible inhabitants in the cage missing.
Without this sort of information it is totally guesswork and the only meaningful response that can be provided is to take it to a reptile knowledgeable vet ASAP.