Neoplasia
Neoplasia is a term designated to signify a new growth of cells in the body. Although all neoplasms are considered to be abnormal, they are designated as either benign (noncancerous) or malignant (cancerous). All tumors, whether benign or malignant, share two things in common: a parenchyma (functional part) that contains proliferating neoplastic cells and a stroma (supportive structure) consisting of connective tissue and blood vessels (Kumar, Abbas, & Fausto, 2005 ).
Benign Neoplasia.
Benign neoplastic cells enter and progress through the phases of the cell cycle in the same fashion as normal cells. Benign neoplastic cells arise from normal cells and tend to retain most of the properties of the cells from which they arose. At the microscopic level, benign cells are euploid, containing the normal chromosome complement. However, because their behavior is not completely normal, it is likely that some alteration in gene regulation is present. Benign neoplastic cells are characterized by increased proliferation or decreased apoptosis (programmed cell death). A major difference in growth characteristics between benign neoplastic cells and normal cells is that density-dependent contact inhibition has been lost. Therefore, benign neoplastic cells continue to grow by expansion into the surrounding tissue.