Skin Lumps or Bumps in Cats
During the course of grooming, playing with or handling your cat, you may discover a lump or bump or or beneath the skin. To learn what it may be, see this table on lumps or bumps on or beneath the skin.
Any sort of lump, bump, or growth found on or beneath the skin is, by definition, a tumor, which literally means a swelling. Tumors are classified as benign when they are not cancer, and malignant when they are.
Classically, a benign growth is one that grows slowly, is surrounded by a capsule, is not invasive, and does not spread. However, there is no reliable way to tell if a tumor is benign or malignant without removing it and examining it with a microscope. If the tumor is benign, it won't come back if it is completely removed.
Cancers usually enlarge rapidly (a few weeks or months). They are not encapsulated. They appear to infiltrate into surrounding tissue and may ulcerate the skin and bleed. A hard mass that appears to be attached to bone or could be a growth of the bone itself is a cause for concern. The same is true for pigmented lumps or flat moles that start to enlarge, then spread out and begin to bleed (melanomas).
A hard gray or pink open sore that does not heal, especially on the feet and legs, should be regarded with suspicion. This could be a skin cancer.
Any unexplained nodules, bumps, or open sores on your cat should be checked by your veterinarian. Most cancers are not painful. Do not delay simply because your cat does not seem to be feeling uncomfortable.
This article is excerpted from “Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.
Copyright © 2008 by Delbert Carlson, DVM, and James M. Giffin, MD. All rights reserved.