At any point each one of us has developed calluses and corns. However, some of calluses and corns are serious and uncomfortable like extreme thickening of the skin is one of the symptoms of having a particular type of esophageal cancer. According to the recent study found there is a relation between having a foot calluses and esophageal cancer with the animals and human as well.
http://www.latinoshealth.com/articles/25160/20170210/callus-a-symptom-of-throat-cancer.htm
Callus: A Symptom Of Throat Cancer? Find Out More Here!