NEOPLASMS

BENIGN & MALIGNANT CELL PATHOLOGY

1. Benign & malignant cells pathology SUDESHNA BANERJEE DUTTA

2. NEOPLASIA The term “neoplasia” means new growth ; the new growth produced is called “neoplasm” or “tumor”. The branch of science dealing with the study of neoplasms or tumors is called oncology ( oncus =tumor, logos=study). Neoplasm may be ‘benign’ when they are slow-growing and localized without causing much difficulty to the host Or ‘malignant’ when they proliferate rapidly , spread throughout the body and may eventually cause death of the host. The common term used for all malignant tumors is cancer .

3. DEFINITION “A neoplasm is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue and persist in the same excessive manner after cessation of the stimuli which evoke the change”. -Willis

4. TYPES OF NEOPLASMS (TUMORS) Benign tumors - They remain localized cannot spread to other sites and are amenable to local surgical removal and patient survives. Oma as a suffix indicates to tumor Epithelial : Adenoma, cystadenoma ( cystic tumors of epithelial origin ), P apilloma

5. ADENOMA

6. PAPILLOMA

7. TYPES OF NEOPLASMS (TUMORS) Malignant tumors - They invade and destroy adjacent structures and spread to distant sites to cause death of patient. Sarcoma ( sar = fleshy) -mesenchymal tissue origin Carcinoma --- epithelial cell origin. Squamous cell carcinoma, Adenocarcinoma

8. Degree of cellular differentiation Differentiation refers to the extent to which the tumor cell resembles its normal counterpart or cell of origin. Benign tumors are very well differentiated & closely resemble their normal counterparts Malignant cells show a wide range of differentiation. Can be very well differentiated or absolutely undifferentiated (anaplastic) Pleomorphism : Variation in shape & size of cells & nuclei Hyperchromasia : Nuclei contain dark stained chromatin Nuclear enlargement Increased mitosis Formation of tumor giant cells

9. Rate of growth Benign tumors are slow growing grow gradually Malignant tumor grow rapidly

10. Circumscription Benign tumors are very well circumscribed & are usually surrounded by a fibrous capsule e.g. lipoma, fibroadenoma or by a compressed rim of surrounding normal tissue. Tumors surrounded by fibrous capsule are called “encapsulated” Malignant neoplasms are generally un-encapsulated & are characterized by their infiltrative pattern of growth. Invasiveness is one important feature

11. WELL CIRCUMSCRIBED POORLY CIRCUMSCRIBED

12. Metastasis Spread of tumor cells from one part of the body to another part . From its site of origin to any distant organ. Invasion of blood vessels ( hematogenous spread ), lymphatics ( lymphatic spread ) or body cavity ( seeding ) Cells may spread by bloodstream or lymphatic channels

13. Implantation Transfer of neoplastic cells from one serous or mucous surface to another by direct contact Body cavities are commonly involved

14. ANAPLASIA: loss of the mature or specialized features of a cell or tissue

15. Factors predisposing for neoplasia Heredity Environment & culture Geographical factors Age Gender UV ray

16. Factors predisposing for neoplasia: Carcinogenic agents Aromatic hydrocarbons (benzene, toluene) Nitrosamines (cosmetics, tobacco, and packing materials) Dyes Aflatoxin B1 (groundnuts, tree nuts, maize, figs) Radiations

17. Diagnostic tests Histopathological sampling Hematological exam Cytologic diagnostic study Immunohistochemistry (tissue distribution of an antigen) Genetic testing