Skin——Epithelioma
CYSTS
Definition. Cysts are hollow tumors filled with fluid or semi-solid contents. They are classified according to their mode of development:
1. Cysts formed in already existing spaces such as sebaceous cysts in the sebaceous glands of the skin; mucous cysts in mucous glands, and distension cysts in ducts of large glands like the salivary, lacteal, hepatic, etc.
2. Cysts of new formation into the tissue spaces from the effusion of blood or plasma.
3. Congenital cysts known as dermoids.
4. Cysts of parasitic origin.
The only cyst with which the chiropodist ordinarily comes in contact is of the sebaceous variety.
Sebaceous Cyst. A sebaceous cyst is a tumor resulting from retained sebum (secretion of the sebaceous glands).
They sometimes, though rarely, are found on the soles of the feet. They range in size from a millet seed to the size of an egg or larger; they may be globular or flattened. They may be single or multiple; the skin over them is normal in color and smooth, or white if distended, red if inflamed. They grow very slowly and ordinarily persist indefinitely, but calcareous changes are common. Not infrequently they break down and ulcerate. The wall is made up of connective tissue lined with epithelium and the secretion if chemically altered, becomes fluid, semi-fluid, cheesy or purulent.