Noncancerous, Precancerous and Cancerous Tumors

The cutaneous horn appears as a funnel-shaped growth that extends from a red base on the skin. It is composed of compacted keratin (the same protein in nails). The size and shape of the growth can vary considerably, but most are a few millimeters in length. Squamous cell carcinoma is often found at the base. It usually occurs in fair-skinned elderly adults with a history of significant sun exposure.