Hyperkeratosis is a word pathologists use to describe an increased number of specialized squamous cells on the surface of the skin. Hyperkeratosis is a non-cancerous change.
The top most squamous cells in the skin form the keratin layer. The cells in the keratin layer are flat and strong and they help to protect the skin. The number of cells in this layer depends on the area of the body. For example, the keratin layer is much thicker on the soles of the feet than it is on the chest.
Hyperkeratosis is a description and not a diagnosis by itself. It is used when your pathologist sees an increased number of cells in the surface of the skin compared to normal. The increased number of cells makes the keratin layer look thicker than normal.