NEOPLASIA Ibrahim Bakhit Yousif Neoplasia Definitions NEOPLASIA literally
NEOPLASIA Ibrahim Bakhit Yousif
Neoplasia: Definitions • NEOPLASIA literally means “new growth” • The term tumor was originally applied to the swelling caused by inflammation; now Tumor is equated with neoplasm • Oncology is the study of tumors or neoplasms (Greek oncos means tumor)
Neoplasia: Definitions • Cancer (Latin for crab) is the common term for all malignant tumors • A Neoplasm is an “abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the change” (Willis, 1952)
Neoplasia differs from Hyperplasia Directly related to the degree of stimulation After abnormal stimulus. E. g. radiation, chemical, virus Once started proceeds, irrespective of the stimulus Regress when the stimulus Persist (irreversible) is removed (reversible) Neoplasia serves no function
Neoplasm It is a type of growth disorders, in which there is a continuous proliferation of cells; usually result in tumors. Differentiated from other changes of growth e. g. hyperplasia, metaplasia, repair, regeneration, by: Purposeless and uncontrollable.
Neoplasia: Nomenclature • All tumors, benign and malignant, have two basic components: • 1) Parenchyma usually referring to epithelial cells in organs • 2) Supportive stroma made up of connective tissue and blood vessels
Benign Tumor Nomenclature • In general, benign tumors are designated by attaching the suffix -OMA to the cell of origin • Tumors of mesenchymal cells generally follow this rule
Benign Tumor Nomenclature( mesenchymal cells) • For example, a benign tumor arising from fibroblastic cells is called a FIBROMA • A OSTEOMA is a benign tumor of osteoblasts, while a benign cartilaginous tumor is called a CHONDROMA
benign epithelial tumors Nomenclature • The terminology of benign epithelial tumors is more complex – based on • classified based on the cells of origin • microscopic architecture • macroscopic patterns
• ADENOMA benign epithelial neoplasms producing gland pattern…. OR … derived from glands but not necessarily exhibiting gland pattern
Adenoma
• Benign epithelial neoplasms producing microscopically or macroscopically visible finger-like referred to as Papilloma • Tumors forming large cystic masses in organs such as the ovary are called Cystadenomas
• When a benign, or malignant, neoplasm produces a macroscopically visible projection above a MUCOSAL surface and projects into a lumen, as in the GI tract, it is termed a POLYP
Polyp
Mesenchymal Malignant Tumor Nomenclature • Malignant tumors arising in mesenchymal tissue are usually called Sarcoma (Greek sar means fleshy) • A malignant tumor arising from fibroblastic cells would be called a FIBROSARCOMA while one developing from osteoblastic cells would be termed an OSTEOSARCOMA
Nomenclature • Benign tumors – Suffix “–oma” is added to the cell type • • Fibrous: fibroma Cartilage: chondroma Bone: osteoma Adipose tissue: lipoma Smooth muscle: leiomyoma Skeletal muscle: rhabdomyoma Blood vessels: hemangioma Epithelial: adenoma (cystadenoma, papilloma)
Epithelial Malignant Tumor. Nomenclature • Malignant neoplasms of epithelial called Carcinoma • Carcinomas can be further qualified: One with a glandular growth pattern microscopically is termed an Adenocarcinoma • A malignant tumor producing recognizable squamous cells arising in any epithelium of the body is termed a squamous cell carcinoma • From Transitional cell: Transitional cell carcinoma
• Malignant tumors – Mesenchymal: sarcoma • • Fibrous: fibrosarcoma Cartilage: chondrosarcoma Bone: osteosarcoma Adipose: liposarcoma Smooth muscle: leiomyosarcoma Skeletal muscle: rhabdomyosarcoma Blood vessels: angiosarcoma – Epithelial: carcinoma • Gland forming: adenocarcinoma • Squamous: Squamous cell carcinoma • Transitional cell: Transitional cell carcinoma (urothelial carcinoma)
Inconsistent, Inappropriate and Confusing Nomenclature • A malignant tumor of melanocytes has for years been called a melanoma when it is better termed a melanocarcinoma • Hamartoma is a malformation (not a neoplasm) that presents as a mass of disorganized tissue indigenous to a particular site; example: nodule in lung containing cartilage
Pulmonary Hamartoma
Inconsistent, Inappropriate and Confusing Nomenclature • choristoma , which is a congenital anomaly composed of a heterotopic rest of cells; example: pancreatic tissue found in the submucosa of the stomach
Pancreatic choristoma in gall bladder
Characterization of Benign and Malignant tumor
Differences Between Benign and Malignant Tumors • These can be discussed under the headings: • 1) Rate of Growth • 2) Local Invasion • 3) Metastasis • 4) Differentiation and Anaplasia
Rate of Growth • Generally most BENIGN tumors grow slowly over a period of years, whereas most CANCERS grow rapidly
Local Invasion • Nearly all benign tumors grow as masses that remain localized (capsulated by connective tissue) • The malignant tumors is invasion and destruction of surrounding tissue
Macroscopically: • Benign: – Round, oval, capsulated • Malignant: – Any shape, no capsule. – Ulcer, fungating, papillary
Metastasis • Metastasis is a mark for tumor as malignant because benign neoplasms do not metastasize • With few exceptions, all cancers can metastasize; malignant glial cell tumors and basal cell carcinomas rarely metastasize
Metastasis: Pathways of Spread • three pathways: • 1) direct seeding of body cavities or surfaces • 2) lymphatic spread • 3) hematogenous spread
Metastasis: direct seeding • Seeding of Body Cavities and Surfaces: may occur whenever a malignant tumor penetrates into a natural “open field” • The peritoneal cavity is most often involved
Metastasis: Lymphatic spread • Lymphatic spread is the most common pathway for carcinomas but sarcomas may use this route
Metastasis: Hematogenous • Hematogenous spread is typical of sarcomas but carcinomas may also use this route • The liver and lungs are most frequently involved secondarily in such hematogenous dissemination
Benign vs malignant tumours Characteristic Benign Malignant Rate of growth Slow Fast Mitosis Few, normal Many, abnormal Nuclei Little altered Large , hyperchromatic Nucleoli Little altered Large Cytoplasmic basophilia Slight Marked Heamorrahge& necrosis slight Extensive
Benign vs malignant tumours Characteristic Benign Malignant Differentiation Good to poor Macroscopic Microscopic Good Well-differentiated Poor De-differentiated Functional --------------Infilteration Usually maintained --------------- Retained, lost or abnormal --------------- Capsule Present well-defined Absent or destroyed Local invasion Absent Frequent metastases No Frequent
Histological grading • Histological estimate of degree of differentiation – Resemblance to normal tissue – Mitotic activity – Pleomorphism • The better the differentiation, the lower the grade, the better the prognosis
Clinical stage • Clinical estimate of the degree of spread – stage I- confined to organ of origin – stage II- spread to the regional LN – stage III – spread to distant LN – stage VI – distant blood-borne metastasis • TNM stage • Staging systems unique to each organ system - Dukes, FIGO, etc.
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Aetiology of tumors • Genetic/hereditary: 1 - Breast carcinoma BRCA 1 & BRCA 2. 2 - Polyposis coli, autosomal dominant, multiple polyps of colon, inevitable malignant change. 3 xeroderma pigmentosum, AR. 4 - Others; retinoblastoma, nasopharyngeal carcinoma • Chemical carcinogens: 1 - aromatic hydrocarbons, coal tar (skin cancer). Cigarette smoke (lung ca) 2 - aniline dye (bladder ca)
Continue of aetiology • Physical agents: 1 - ionizing radiation; skin ca, CML, osteosarcoma. 2 - UV light; BCC, SCC, MM 3 - heat: pipe smoker lip ca. • Chronic diseases: Chronic discharging sinuses & old burn (SCC), ill fitting denture (SCC), UC (CA colon), liver cirrhosis (HCC), undescended testes (seminoma)
• Infections: 1 - parasite; e. g. schistosomiasis~ SCC urinary bladder. clonorchus sinensis~ cholangiocarcinoma. 2 - virus; EBV~ Burkitt’s lymphoma& NPC. HBV~ hepatocellular ca. HPV~ cervical ca. HTLV~ T-cell leukaemia/lymphoma • Hormones: 1 - estrogenes excess~ ca endometrium, ca breast, liver adenoma. 2 - some tumors are hormone dependant~ ca prostate
Effects of tumours
Local effects of tumours q. Pressure on nearby structures. §veins→stasis→oedema→thrombosis, §nerves →pain ; paralysis §brain →fits ; paralysis §obstruction qinvasion into nearby structures §destruction, necrosis §heamorrahge →anaemia §Ulceration §secondary infection
General effects of tumors • Cachexia--raised BMR; malnutrition • Pyrexia—raised BMR; infection • Anaemia—heamorrhage, marrow depression • Immunological depression • Carcinomatous syndromes—neuropathy, myopathy, dermatopathy
Cachexia
Hormonal effects of tumours q. Overproduction of hormones v (endocrine origin) • ACTH—pituitary adenoma • PTH---parathyroid adenoma v. Ectopic production(non- endocrine) • ACTH---oat cell carcinoma lung • PTH---SCC lung q. Hormone deficiency
Production of fetal proteins (tumour markers) • • • Examples : Alfa fetoprotein malignant germ cell tumours. hepatocellular carcinoma Carcinoembryonic antigen GIT cancers CA 125 (OVARIAN), CA 19 -9(PANCREAS 0 etc May be used as tumour markers Used in diagnosis, determination of orgin, therapeutic monitoring and recurrence.
Thank you for your attention if you have any questions, feel free to interrupt me at any time
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