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. Despite their benign characteristics, these tumors should also be removed because they can become quite large and impinge on surrounding tissues or impede limb movement. They are also difficult to distinguish from infiltrating lipomas or from malignant liposarcomas. Sebaceous Gland Tumors are also common.