My dog has a skin-colored nipple-like lump. Is it a mast cell tumor?

That mass could be several things. Red raised hairless masses can be benign growths such as warts, histiocytomas, reactions or infected hair follicles. They can unfortunately also be malignant grows such as Mast Cell Tumor or Plasmacytoma. I would recommend to have it checked out by the vet who may be better able to tell how concerned you should be by palpating the mass and the surrounding lymphnodes. The good news is that the majority of masses are benign but it's always better to be safe. Thank you for using Petco Pet Education Center, formerly Petcoach!

Hopefully it's nothing but any red, raised mass is concerning for a skin cancer called Mast Cell Tumor. Many other lesions though can look this way but I think it's always best to play it safe and have it tested. Aspirations of a mass are generally quick and easy and most pets tolerate them well. I hope this helps and please feel free to post any additional questions.

Hi there and thank you for using Petco Pet Education Center, formerly Petcoach to address your concerns. Based on the photo you provided, this could be a number of things. Tornado is very young, so there is a chance that this could be something called a histiocytoma. This type of mass is commonly seen in younger animals and is non-cancerous that typically goes away on its own. Some cases need to be surgically removed if they are not resolving or if they are growing in size.The other possibility is that it is something cancerous. Mast cell tumor would certainly be on my list of rule outs. To be certain this is nothing to be concerned about, I would recommend that you take Tornado in to be seen by a veterinarian so that the most appropriate diagnostic and treatment recommendations can be made. I hope this helps guide you in the right direction!

Yes, this may just be a benign growth like a skin tag, but I cannot make a definitive diagnosis without seeing him in person. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. I hope this helps!

Thanks for using Petco Pet Education Center, formerly Petcoach! This could be a benign or malignant growth. There is no way of knowing what it is just based on its appearance. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have him evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good day!

I can see that Sir Nicholas has a small, raised, dark lesion by his nipple. This can be a mass under the skin, which may be malignant (likely to spread) or benign (unlikely to spread). I recommend having this area looked at by a vet. They will be able to either remove the mass completely and determine exactly what it is, or take smaller samples using a needle. I hope this helps and that Sir Nicholas is doing well!

This looks like a mass. It looks quite benign such as a wart or skin tag, however it is impossible to know for sure without testing the lump. You could have the lump tested/removed or simply monitor it for changes. I wouldn't be overly concerned about it.