neoplasia introduction, nomenclature, classification of tumours

neoplasia introduction, nomenclature, classification of tumours

1. NEOPLASIA Dr. DUSSA VAMSHIKRISHNA , M.D ( HOMOEO)

2. LEARNING OBJECTIVES OF TODAYS LECTURE Definition Nomenclature Classification

3. The term ‘Neoplasia’ (LATIN) means New Growth. Neoplastic cells lose control and regulation of replication and form an abnormal mass of tissue. The new growth produced is called ‘Neoplasm’ or ‘Tumour’.

4. Definition of Neoplasm or Tumour A mass of tissue formed as a result of A bnormal, E xcessive, U ncoordinated, A utonomous and P urposeless P roliferation of cells even after cessation of stimulus for growth which caused it. TUMOUR = NEOPLASM

5. The branch of science dealing with the study of neoplasms or tumours is called ONCOLOGY ( oncos =tumour, logos=study).

6. Nomenclature: Neoplasms may be ‘BENIGN TUMOURS’ Slow-growing. Localised. ‘MALIGNANT’. Proliferate rapidly. Spread throughout the body.

7. CLASSIFICATION OF BENIGN TUMOURS: The benign tumours derive their nomenclature on the basis of the tissue involved (CELL ORIGIN). They end with suffix - OMA

8. BENIGN TUMOURS EPITHELIAL ORIGIN MESENCHYMAL ORIGIN PAPILLOMA Squamous Cell Papilloma Transitional Cell Papilloma ADENOMA Glandular Adenoma Liver cell Adenoma ORIGIN Squamous Cell Transitional Cell ORIGIN Glandular epithelium Hepatocytes Called as Called as Adipose tissue Adult fibrous tissue Cartilage Bone Smooth muscle Skeletal muscle Blood vessels Lymph vessels Meninges Lymphoid tissue Nerve sheath Nerve cells Lipoma Fibroma Chondroma Osteoma Leiomyoma Rhabdomyoma Haemangioma Lymphangioma Meningioma Pseudolymphoma Neurilemmoma Ganglioneuroma

9. CLASSIFICATION OF MALIGNANT TUMOURS: Malignant tumours of epithelial origin are called CARCINOMAS (CANCERS) While Malignant mesenchymal tumours are named SARCOMAS (SARCOS = fleshy) However, some cancers are composed of highly undifferentiated cells and are referred to as undifferentiated malignant tumours.

10. The word ‘cancer’ means crab, thus reflecting the true character of cancer since ‘it sticks to the part stubbornly like a crab’. The common term used for all malignant tumours is cancer.

11. MALIGNANT TUMOURS EPITHELIAL ORIGIN (CARCINOMAS) MESENCHYMAL ORIGIN (SARCOMAS) Squamous cell (Epidermoid) Carcinoma Transitional cell Carcinoma Adenocarcinoma Hepatoma ( Hepatocellular carcinoma) ORIGIN Squamous Cell Transitional Cell ORIGIN Glandular epithelium Hepatocytes Called as Called as Adipose tissue Adult fibrous tissue Cartilage Bone Smooth muscle Skeletal muscle Blood vessels Lymph vessels Meninges Lymphoid tissue Haemopoietic cells Nerve sheath Nerve cells Liposarcoma Fibrosarcoma Chondrosarcoma Osteosarcoma Leiomyosarcoma Rhabdomyosarcoma Angiosarcoma Lymphangiosarcoma Invasive meningioma Lymphoma Leukaemias Neurogenic sarcoma Neuroblastoma

12. SPECIAL CATEGORIES OF TUMOURS 1. Mixed Tumours 2. Teratomas 3. Blastomas (Embryomas) 4. Hamartoma 5. Choristoma

13. 1. Mixed tumours: When two types of tumours are combined in the same tumour, it is called a mixed tumour. Adenosquamous Carcinoma: It is the combination of Adenocarcinoma and Squamous Cell Carcinoma in the endometrium. 2. Carcinosarcoma: It is the rare combination of malignant tumour of the epithelium (carcinoma) and of mesenchymal tissue (sarcoma) such as in thyroid.

14. Teratomas are rare type of neoplasms which contain fully developed tissues/organs like hair, bone, muscle etc. Develops from pluripotent cells i.e., from the three germ layers cells. 2 . Teratomas :

15. Teratomas: 95 % are BENIGN OR MATURE - most of the ovarian teratomas – in women.(more common) 5 % are MALIGNANT OR IMMATURE- most of the testicular teratomas- in men.

16. Most common sites for teratomas are: OVARIES TESTIS But they occur at extra-gonadal sites as well. Mainly in the midline of the body such as in the head and neck region, Mediastinum Retroperitoneum , Sacrococcygeal region etc

17. Blastomas or Embryomas are a group of malignant tumours develop from the blastema (precursor cells/blast cells) of organs. It typically affects children rather than adults. 3. Blastomas (Embryomas)

18. BLASTEMA/BLAST CELLS OF THE ORGANS AND TISSUE DURING EMBRYOGENESIS Blastomas (Embryomas)

19. Each kind of blastoma is given its own name depending on where it’s located in the body. For example, Nephroblastoma (Wilm’s tumour) is found in the kidney. Retinoblastoma is found in the Eye. Medulloblastoma is found in Brain . Hepatoblastoma is found in Liver.

20. Features: All Blastomas are childhood tumours. They usually present before the age of 5 years, and many are present at birth. They are malignant in nature. Exception to this case: (BENIGN IN NATURE) Chondroblastomas from chondroblasts Osteoblastomas from osteoblasts .

21. Retinoblastoma Nephroblastoma ( Wilm’s tumour)

22. 4. Hamart oma It is a benign tumor made of mature but disorganized cells of tissues indigenous to the particular organ. In Greek  hamartia,  meaning “defect”. It is considered a developmental error and can occur at a number of sites. Here the disorganized cells of tissues are arranged in a mass (Tumour).

23. E.g. Hamartoma of the lung consists of mature cartilage, mature smooth muscle and epithelium. Thus, all mature differentiated tissue elements of bronchus are present in lung but are jumbled up as a mass

24. Choristoma  is a tumor-like mass consisting of normal cells in an abnormal location (Foreign to the site) (Ectopic location). The mature tissue elements not normally present at the site of occurrence. It is a developmental defect. It is not a true tumour. Eg: Presence of Pancreatic tissue in Stomach wall. 4. Chorist oma .