After cutting the corns, this thing in the middle appears. The deeper you cut, the bigger it is. Can someone tell me what this is and what's going on?

Cornus officinalis, also known as meat thorn, often grows on the toes and the front of the soles of the feet. This disease is mostly caused by the long-term stimulation of the skin of the foot due to tight shoes or deformity of the foot bones.

The horns are conical horny hyperplasia induration, the number is uncertain, the roots are deep, the skin is thickened, and the top is prominent, which often affects walking because of pain. There are many treatments for corns, and various corrosive drugs, such as salicylic acid, are commonly used. You can cut a round hole in the center of the plaster, the size of which is the same as that of the corns, stick it on the affected area, expose the corns, sprinkle salicylic acid powder, and then cover it with the plaster. Generally, the dressing should be changed once every 3 to 5 days. After removing the residual powder before dressing change, soak your feet in hot water and scrape off the softened keratin until the corns are completely removed. Friction and squeezing should be reduced, and appropriate soft-soled shoes should be worn, or sponge pads should be used to reduce local oppression. If you have flat feet, you should wear a orthopedic shoes.