Histiocytoma is a type of benign tumor that typically arises from histiocytes, a kind of immune cell found in the skin. It often appears as a small, raised, and firm lump, usually on the skin of dogs, particularly in younger animals. While these tumors are generally harmless, they can sometimes be mistaken for more serious conditions. In most cases, histiocytomas will resolve on their own without treatment. However, if a tumor is persistent or bothersome, a veterinarian may recommend surgical removal. Regular check-ups can help monitor any changes in the skin, ensuring that any potential issues are addressed promptly.