SQUAMOUS CELL CARCINOMA

(original graphic by marvistavet.com)

The squamous cell carcinoma is often one of the most heart-breaking tumors any living thing can develop. The tumor is rapidly invasive locally but does not spread in the way we usually think of a cancer spreading until late in its course. This would seem to be a positive aspect lending itself to potential surgical removal and cure but unfortunately, this is usually not the case. The tumor tends to arise in locations where surgery is challenging or where the tumor is not detectable until surgery is not possible.

Before reviewing some of the more classical presentations of this tumor, let us address what squamous cells are. Our bodies must interface with the outside world in several areas: our skin, our mouth and nose, our entire gastrointestinal tract, respiratory tract and even urinary and reproductive tracts. All these areas are accessible from the outside world if not directly like the skin, then via some sort of opening like the urinary or GI tract. The cells that line these are areas are called “epithelial cells” and then can take many shapes depending on if their job is to protect us from the environment (skin), absorb material from the environment (GI tract), or perform some other sort of job (respiratory tract.) Epithelial cells also line our body cavities, the outside of our organs and blood vessels, forming a thin casing.

“Squamous” epithelial cells are flat plate-like cells which form layers, a sort of a microscopic armor against the wear and tear that comes from interfacing with the environment. The squamous cells make up the outer layer of the skin, nose, and mouth.

The squamous cell carcinoma (sometimes called simply a “squame”) arises when the body’s squamous cells become tumorous. Some classical presentations include:

• Sun-induced Skin Cancer (especially in white faced cats and white dogs)
• Nasal Squamous Cell Carcinoma of the Cat
• Oral Squamous Cell Carcinoma of the Cat
• Nasal Squamous Cell Carcinoma of the Dog (especially long nosed breeds)
• The Nail Bed Squamous Cell Carcinoma of the Dog
• The Squamous Cell Carcinoma in situ/Bowen’s Disease

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