Neoplasia -An Introduction

Neoplasia/Neoplasm

Neoplasia or neoplasm refers to new growth, new mass or abnormal proliferation.

Tumor

Previously, any swelling caused by inflammation was known as tumor. Now it is only reserved for neoplastic swelling.

Oncology

Oncology is the study of tumors (neoplasms), both benign and malignant.

Oncogenesis

Pathogenesis of neoplasm is known as oncogenesis.

Cancer

Any malignant tumor is known as cancer.

Carcinogenesis

Carcinogenesis is the pathogenesis of cancer.

Prognosis

Prediction of probable source and outcome of disease is called prognosis.

Neoplasm

Definition

Neoplasm is abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue and persists in the same excessive manner after termination of the stimuli which evoked the change.

Non-lethal genetic damage lies at the center of neoplasia.

If the damage is lethal, it leads to cell death.

Non-neoplastic proliferation

The the proliferation is controlled and reversible, it is non-neoplastic. Examples of non-neoplastic proliferation includes:

1. Hypertrophy –increase in size of cells
2. Hyperplasia –increase in number of cells
3. Metaplasia –change in cell type
4. Dysplasia –border line case, before progression to cancer. It is the disordered type of proliferation

Neoplastic proliferation

If the proliferation is uncontrolled and irreversible, it is known as neoplastic proliferation. It may be:

a. Benign: localized and non-invasive

b. Malignant (cancer): spreading and invasive, tumor is going to leave original place and spread.

Metastasis is known as the distant spread of tumor.