Expert: Jessica - 12/20/2009

Question
Hello Jessica,
I have a male cat who is approximately 7 years old and he has developed a lump directly underneath his nipple.  It feels very hard and swollen but he does not appear to have any discomfort in this area when I feel the lump.  Can you please advise of any possible diagnosis and kindly let me know if an immediate vet visit is in order.
Thanks for taking the time to review my question.
Lisa.

Answer
Hi Lisa.  I do think a prompt vet visit is in order.  Although male mammary tumors are somewhat uncommon, this always must be suspected when a lump is found under a nipple.  If the growth appears characteristic of a tumor, your vet will want to do a biopsy.  Some mammary tumors are benign, but most are malignant and should be removed immediately in the hopes of preventing the cancer from spreading.

Occasionally, a nipple will become impacted with dead skin cells and can become infected.  Though these lumps are not especially hard, it still could be a possibility.  The vet may choose to express the material from the nipple, or antibiotics alone may be prescribed.

There are also some harmless cysts and tumors that can develop just under the skin, such as sebaceous cysts and fatty tumors (lipomas).  These tend to be very soft growths, however, because they are fluid-filled or fatty deposits respectively, and I’d be surprised if this is what your kitty’s lump is.  Nevertheless, if either of these is what’s diagnosed, there is no treatment necessary.

Best of luck – I hope it turns out to be nothing of concern!

Jessica