Finding an unusual lump or patch in bacon is often just a natural variation in fat, connective tissue, or muscle structure.
Since bacon comes from real animal meat, dense fat deposits, natural folds, and rubbery cartilage are completely normal and safe.
However, you should discard the bacon if you notice warning signs of spoilage like sour odors, excessive slime, green discoloration, or mold.
When in doubt, check expiration dates, contact the manufacturer with photos, or follow the basic rule: throw it out if it seems unsafe.