Benign epithelial tumors
There are two main types of benign epithelial tumors, depending on the type of the proliferating epithelium : papilloma and adenoma.
Papillomas appear in stratified squamous epithelium (skin, oral and pharynx, vagina, cervix, and in areas of squamous metaplasia), urothelium and galactophore ducts.
Adenomas are benign tumors of glandular epithelium (parenchyma organs with endocrine and exocrine secretion) and of unistratified mucosa of hollow organs.
Ovarian cystadenoma and fibroadenoma of the breast are special types of adenomas.