The simplest answer to this question is – any new bump should probably be looked at.
Oftentimes, what is required is a fine needle aspirate. Fine needle aspiration is a type of biopsy procedure wherein a thin needle is inserted to take some cells out of the lump to determine whether or not it’s something that might be concerning.
A lump can range anywhere from a mat of fur, to some type of benign cyst, all the way up to a severe and aggressive malignancy.
Statistically speaking, most bumps are not major medical problems. The hang-up is that you never can tell until you check so schedule an appointment with your veterinarian as soon as you can.