Tumors and Neoplasia
Introduction and Classification
Neoplasia and tumor definitions
Features of neoplasia
Classification of tumors
Naked eye appearance including the organ of origin
Histogentic (including embryological classification
Difficulties of this classification
Histological classification
Classification according to the behavior
Characteristics of benign tumors
Characters intermediate tumors (locally malignant tumors)
Examples of locally malignant tumors
Characteristics of malignant tumor
Characteristics of carcinoma in situ
Etiological classification
Functional classification
Classification currently used
Structure and effects of some common tumors
General Characters of Tumors
Benign epithelial tumors
Tumors arising from surface epithelium (papillomas or papillomata)
Squamous cell papilloma
Columnar cell papilloma
Glandular benign tumors (adenomas or adenomata)
Varieties are known
Simple adenoma
Cystadenoma
Fibroadenoma
Benign connective tissue tumors
Benign tumors of fibrous tissue
Fibroma
Desmoid tumor
Benign tumors of myxoid tissue
Myxoma
Benign tumors of fat
Lipoma
Benign tumors of cartilage
Chondroma
Benign tumors of bone
Osteoma
Benign tumors of muscles
Myoma
Tumors of never sheath
Schwanoma, neurilemmoma or neuroma
Malignant epithelial tumors (carcinomas or carcinomata)
Three main types of covering epithelial carcinomas are recognized
Squamous cell carcinoma
Carcinoma in situ (intra epithelial carcinoma
Invasive carcinoma
Grading of squamous cell carcinoma (Broder’s classification)
Glandular carcinoma
Adenocarcinoma
Carcinoma simplex (undifferentiated or spheroidal cell carcinoma
Scirrhous carcinoma
Medlullary carcinoma (Encephaloid carcinoma
Mucoid carcinoma (colloid or mucinous carcinoma
Grading of glandular carcinoma
Intermediate epithelial tumors (Locally Malignant)
Basal cell carcinoma;“Rodent ulcer
Malignant tumors of connective tissue (sarcomas or sarcomata)
Fibrosarcoma
Liposarcoma
Leiomyosarcoma
Malignant Fibrous Histiocytoma
Rhabdomyosarcoma
Developmental tumors and tumor like conditions
A malformation
Forms or types of malformations
Agenesis
Aplasia
Hypoplasia
Failure of fusions
Failure of separations
Failure of canalization
Local gigantism
Supernumerary organs
Ectopia, heterotopia or aberrance
Choristomas
Hamartoma
Tumors derived from the germ cells
Seminoma and dysgerminoma
Teratoma
Extra-uterine choriocarcinoma
Yolk sac tumor
Teratoma
Ovarian teratomas
Testicular teratomas
Embryonic tumors of infancy
Nephroblastoma or Wilm’s tumor (Kidney)
Hepatoblastoma (Liver)
Neuroblastoma (Sympathetic ganglia and adrenal medulla)
Medulloblastoma (Brain)
Retinoblastoma (Eye)
Embryonic sarcoma, rhabdomyosarcoma or sarcoma
Hamartoma
Differences between hamartoma and teratoma
Types of hamartomas
Vascular hamartomas
Hemangioma
Lymphangioma
Melanotic hamartoma (melanocytic nevus)
Junctional nevus
Intradermal nevus
Combined nevus
Malignant melanoma
Spread of malignant tumors
Mechanisms of tumor spread
Clonal expansion of a transformed cell, growth, diversification and angiogenesis
Formation of a metastatic subclone
Adhesion of the sub-clone to and invasion of the basement membrane (BM)
Passage through the extracellular matrix (ECM)
Intravastion.
Interaction with host lymphoid cells
Formation of tumor cell embolus
Adhesion to the vascular basement membrane (BM)
Extravastion
Formation of metastatic deposits
Angiogenesis
Formation of secondary growth
Routes of tumor spread
Direct spread
Embolic spread
Lymphatic spread
Blood spread
“Factors affecting distribution of metastasis”
The Metastatic power of tumor “The speed of metastasis”
Trascoelomic spread
Spread along epithelial lined spaces
The Etiology and Incidence of Tumors
Theories of tumor origin
Cell rest Conheim theory: cell rest origin
Single clone theory
The field of growth theory
Causes of human cancer
Chemical carcinogens
Physical carcinogenic agents
Viruses and bacteria
Hereditary predisposition
Hormonal imbalance
Cancer following chronic diseases
Chemical Carcinogens
The “Chemical agents
“Aromatic polycyclic hydrocarbons
Aromatic amines
The mode of its action
The azo compounds
Heavy metals
Other chemical carcinogens
Carcinogens of natural origin
Aflatoxins
Cycasine
The bacterial metabolites
Initiation and promotion theory
Action of chemical carcinogens
Direct acting carcinogens
Procarcinogens
Physical Carcinogenic Agents
Ionizing radiations
Ultraviolet radiations
Thermal radiation
The latent period
Viruses and Neoplasia
DNA oncogenic viruses
Herpes viruses
Papova viruses
Hepatitis B virus and hepatitis C virus
The oncogenic RNA viruses (pocorna viruses)
Human T-lymphtropic virus (HTW-1
Bittner virus
Hereditary Predisposition to tumor formation
Hormones and Neoplasia
Hormone dependent tumors
Cancer following chronic disease
Precancerous lesions
Carcinogenesis
