What term refers to a growth of thickened skin?

The term that refers to a growth of thickened skin is keratoma. Keratomas are often characterized by their hardened, thickened areas of skin, which can result from an increase in keratin production. This condition can occur due to pressure, friction, or other forms of irritation.

Lesions describe any abnormal tissue change, which can include various skin disorders but does not specifically denote thickened skin. A nodule refers to a small, rounded mass that can be solid or filled with fluid, but it does not specifically describe the thickening of skin texture. A fissure is a deep split or crack in the skin, which is different from just having thickened skin.

Thus, keratoma accurately captures the concept of thickened skin growth, making it the correct choice in this context.