1. Neoplasia 1

2. a) Definition b) Terminologies

3. Neoplasia “new growth” Definition: “an abnormal growth of tissue, the growth of which exceed and is uncoordinated with that of normal tissues and persists in the same excessive manner after cessation of the stimuli which evoke the changes”.

4. Characteristic of neoplastic cells Clonal:The entire population of cells in a neoplasm arose from a single cell Autonomous-independent of growth and regulatory influences Excessive Disorganized Fundamental to the origin is genetic abnormality, allowing excessive & unregulated proliferation that is independent of physiologic growth regulatory stimuli. *

5. Common terminologies Tumour: neoplasm Oncology : (gk. Oncos = tumour) Cancer : Common term for all malignant neoplasms. (latin: cancer = crab) Based on behavoiur: Benign,malignant Components: parenchyma (neoplastic), stroma (non-neoplastic)

6. Characteristics of benign & malignant tumours Differentiation & anaplasia Rate of growth Local invasion Metastasis

7. Common terminologies in histopathology Dysplasia Invasive carcinoma Differentiation Grade Anaplasia Pleomorphic,hyperchromatic,atypical mitosis,tumour giant cells

8. Dysplasia Disorderly growth and maturation of cells that are not benign but not obviously malignant either. Loss in the uniformity of individual cells & in their architectural orientation Premalignant condition Stage linking non-neoplastic (metaplasia, hyperplasia) and malignancy (carcinoma- in-situ)

10. Carcinoma-in-situ

11. Differentiation Degree of resemblance of malignant (parenchyma) cells to normal cells both in morphology and function Expression of genes in a tissue specific manner

12. Benign tumours are well differentiated

13. Differentiation ….. Malignant tumours lack differentiation Degree of differentiation is grade of a tumour Well differentiated Moderately differentiated Poorly differentiated

16. Anaplasia Anaplasia: (to form backwards) Parenchymal cells that are not differentiated,with loss of structural & fucctional differentiation of normal cells Seen in malignancy.

17. Morphological features of anaplasia Loss of polarity Pleomorphism: variation in size &shape Abnormal nuclear morphology Nuclear pleomorphism (anisokaryosis) Hyperchromatic –usually increased in amount and irregularly distributed “clumped” High N:C ratio (normal 1:4-1:6) Nucleoli : ↑ size

19. Morphological features of anaplasia…. Atypical Mitoses – Increased number Abnormal morphology tumour giant cells, necrosis

21. Words not to be confused with neoplasm

22. Hamartoma Mass of disorganized but mature specialized cells native to the organ in which the structures arose. E.g. pulmonary hamartoma

23. Choristoma Mass composed of normal mature cells or tissues in the wrong location (heterotopic rest) Eg ectopic panceas in the stomach.

24. Other terminologies that you already know……

25. Atrophy Shrinkage in the cell size by loss of cell substance. Can be physiologic or pathologic

26. Hypertrophy ↑in the size of the cells, →increased size of the organ. Due to synthesis of more structural components. Occurs in non-dividing cells. Can be physiologic or pathologic.

27. Physiological Hypertrophy eg skeletal muscle hypertrophy Uterus & lactating breast show both hyperplasia and hypertrophy due to hormonal stimulation.

28. Pathological hypertrophy Cardiac hypertrophy in chronic haemodynamic overload e.g. in systemic HT,coarctation of aorta,AS & MS with or without regurgitation. Initially compensatory, later decompensates →CCF

30. Agenesis Complete absence of an organ or lack of specific cells within the organ Eg Sertoli cell only syndrome

31. Metaplasia Metaplasia is a reversible change in which one adult cell type (epithelial or mesenchymal) is replaced by another adult cell type. It is an adaptive substitution of cells that are sensitive to stress by cell types better able to withstand the adverse environment. E.g. squamous metaplasia in bronchial epithelium.

32. Thank you