Although benign, it is important to obtain a definitive diagnosis to rule out its malignant counterpart, hemangiosarcoma. Hemangiomas tend to ulcerate. Again, surgical removal is recommended. Histiocytomas are another common skin tumor. The exact cell of origin of this tumor is unknown.
Some evidence points to a viral cause, although no specific virus has yet been identified.
Again, this type of tumor is difficult to diagnose and it can be confused with some malignant neoplasms. Although benign histiocytomas can resolve spontaneously within two to three months, the best course of action is to have them surgically removed and biopsied. Lipomas are quite common in older dogs. They usually appear as slow-growing, soft, discrete, round masses right under the skin. They are usually freely movable.