Malignant or Benign Canine Skin Cancer?

This article will discuss the symptoms and diagnosis of mast cell tumors in dogs. Skin cancers can resemble benign tumors.  A biopsy should be performed on any lump or bump that is questionable.

Definition of Dog Skin Cancers

Skin cancers are inclusive of Mast Cell Tumors (MCTs), which are common in older dogs, and frequently found on the hind legs, lower abdomen, and foreskin of the penis. Mast cells comprise about 20% of the dog’s skin cells.

Approximately 30% of all tumors in dogs are tumors of the skin, or subcutaneous tumors. Of these, 70 – 80% are benign. The remaining 20 – 30% are malignant. Of the malignant tumors, about 20% are Mast Cell Tumors (MCTs).

Dog Skin Cancers Symptoms & Diagnosis

The tumors can appear on the skin, or in the subcutaneous tissue. They can emerge singly, or in multiples, and can be smooth, bumpy, or even ulcerated.

For some dogs, other bodily signs of Canine Skin Cancer include:

• Vomiting
• Blood in the stool
• Blood clotting abnormalities

A biopsy is required to confirm a mast cell tumor diagnosis.  MCTs that arise in the following areas are more likely to be malignant:

• Nail bed
• Genital areas
• Muzzle
• Oral cavity

MCTs that originate in deeper tissues such as the liver or spleen present an especially severe situation. Tumors that have been present for quite a while are more likely to be benign. The rapidity of cell proliferation can be determined via an Argyrophilic Nuclear Staining Organizing Regions count. A higher AgNOR count correlates to an increased likelihood of malignancy.

Along with these factors, the grade and stage of the tumor will determine the course of treatment and prognosis.

Get the information you need about canine cutaneous and mast cell tumors in your copy of Canine Cancer SECRETS.