Introduction to Neoplasia Epidemiology and Classification of tumours PDF

Introduction to Neoplasia, Epidemiology and Classification of tumours Ms. Norhidayah Rosman MSc.(Medicine) Unit of Pathology  Topic Outcomes Objectives: The objective of this lecture is to discuss neoplasia, benign and malignant neoplasm...

Introduction to Neoplasia, Epidemiology and Classification of tumours Ms. Norhidayah Rosman MSc.(Medicine) Unit of Pathology  Topic Outcomes Objectives: The objective of this lecture is to discuss neoplasia, benign and malignant neoplasms. Describe all terms associated with neoplasia. State cancer incidence of common cancers. Recognise and list tumours based on parenchymal cell type and its origin (epithelial or mesenchymal). Describe the characteristic features of benign and malignant neoplasms.  NEOPLASIA “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.” - Dr. RA Willis-  NEOPLASIA A neoplasm can be defined as a disorder of cell growth that is triggered by a series of acquired mutations affecting a single cell and its clonal progeny. Tissue Differentiation The degree to which tumor cells resemble their cell of origin.  Well-differentiated Tumour cells look very much like their cell of origin. Poorly-differentiated Tumor barely resemble their cell of origin. Histology features  BASIC COMPONENTS Parenchyma Stroma The supporting, host-derived, non- The tissue layers which play the neoplastic stroma main role in the function of the Made up of connective tissue, blood organ vessels & host-derived inflammatory Made up of transformed / neoplastic cells cells Important to the growth of neoplasm Largely determine its biological – carries the blood supply & provide behavior support for parenchymal cell’s Tumor derives its name growth A B  TUMOR CONSISTENCY DEPENDS ON AMOUNT OF STROMA Soft and fleshy: Stone hard consistency These tumors have scanty stroma.  Type of Tumor Histology ACINAR  LEPIDIC Tumor cells proliferating along the surface of intact alveolar walls without stromal or vascular invasion pathologically PAPILLARY  MICROPAPILLARY Myoepithelial (MEP) Bulbous expansion of Luminal the tips epithelial (LEP)  CRIBRIFORM Myoepithelial (MEP) Tumour cells Luminal Holes/ epithelial (LEP) Microcyts in the tumour COMEDO Myoepithelial (MEP) Necrotic cells Luminal epithelial (LEP)  SOLID Solid sheets or nests of polygonal tumor cells without features of lepidic, acinar, papillary, or micropapillary growth  POLYPS Mass of tissue protruding into the lumen of the bowel. Polyps can be pedunculated, or sessile and can vary in size. They can occur as solitary or multiple polyps.  DIVISION OF NEOPLASIA Benign Malignant Non-cancerous Cancerous  Nomenclature of Benign ~ oma” suffix at the end of the epithelial origin Derivation of benign tumors of epithelial origin Arise from ectoderm (e.g., squamous and transitional epithelium) Endoderm (e.g., glandular epithelium) Mesoderm - connective tissue origin  Benign tumors of epithelial origin Liver cell adenoma Follicular adenoma thyroid Cystadenoma Cysts are abnormal, closed sac-like structures within a tissue that contain a liquid With solid areas consisting of glands Benign tumors of epithelial origin Adenoma Papilloma (finger like projections)  Nomenclature of Malignant “~ sarcoma”(mesenchymal tissue) or “~carcinoma” (epithelial tissue) at the end of the cell origin  CARCINOMA Carcinomas of non-glandular epithelium: prefixed by the name of the epithelial cell type. Eg: squamous cell carcinoma and transitional cell carcinoma. Carcinomas of glandular epithelium: adenocarcinomas, coupled with the name of the tissue of origin; Eg: adenocarcinoma of the breast, adenocarcinoma of the prostate, renal cell adenocarcinoma, adenocarcinoma of the stomach.  MALIGNANT MESENCHYMAL TUMORS Malignant neoplasms arising in “solid” mesenchymal tissues or its derivatives are called sarcomas Malignant neoplasms arising from the mesenchymal cells of the blood are called leukemias or lymphomas.  TERATOMA Tumour that arises from all three germ cell layers (Ectoderm, Mesoderm and Endoderm) - so you can see bone, cartilage, thyroid tissue, neural tissue Composed of mature tissues– like hair, sebaceous glands, skin, and teeth - Benign  CARCINOMA VS SARCOMA Carcinoma Sarcoma Origin Epithelium tissue Mesenchymal tissue Preferred route Predominant in lymphatics. Predominant in hematogenous. of metastasis Age group Occurs primarily in people Affect both young and old over 50 years of age. people. Most common Include cancer of lungs and Include bone, muscle, or cancer site breast. of lymph nodes. Frequency Common. Rare. Rate of growth Fast. Slow. Morphology Firm to hard tumor Soft and fleshy (less stroma) Microscopic Mostly, cells arranged in Mostly, cell arranged groups individually Which one is carcinoma & sarcoma? A B  Benign vs Malignant Benign (noncancerous) Malignant (cancerous) Attach suffix-oma to the cell type Follows benign tumors with certain from which tumor arises additions & exceptions Relatively innocent Lesion can invade Remain localised Can destroy adjacent structure Amenable to local surgical removal Spread to distant sites (metastasize)- cause death Example: Example: Fibroma, papillomas, granuloma, Squamous cell carcinomas lipoma More nomenclature of tumors, Robbins Basic Pathology, Page 192  Comparison Benign & Malignant Characteristics Benign Malignant Differentiation Well differentiated Some lack of differentiation /anaplasia Structure sometimes typical of (anaplasia) tissue of origin Structure often atypical Rate of growth Usually progressive & slow Erratic May come to a standstill/regress May be slow to rapid Mitotic figure rare & normal Mitotic figures may be numerous & abnormal Local invasion Usually cohesive, expansile, well- Locally invasive demarcated masses that do not Infiltrating surrounding tissue invade/infiltrate surrounding Sometimes maybe misleadingly normal tissues cohesive & expansile Metastasis Absent Frequent More likely with large undifferentiated primary tumors BENIGN VS MALIGNANT Nomenclature of tumors, Robbins Basic Pathology, Page 192  CANCER INCIDENCE IN MALAYSIA  CANCER INCIDENCE IN MALAYSIA THANKS! Do you have any questions? Ms. Norhidayah Rosman [email protected] 012-8351810