Carcinogenesis Pre-learning 1.pdf

Pathology Concepts 1.04 Carcinogenesis – Tumour characteristics Dr. Hurnik BMS 100 Week 9 Video Link https://ccnm.ca.panopto.com/Panopto/Pages/Vie wer.aspx?id=fc6eb8be-641f-407a-9225afbb000bb85c Today’s Overview Pre-learning: Definitions & tumour characteristics Risk factors In class: Model...

Pathology Concepts 1.04 Carcinogenesis – Tumour characteristics Dr. Hurnik BMS 100 Week 9 Video Link https://ccnm.ca.panopto.com/Panopto/Pages/Vie wer.aspx?id=fc6eb8be-641f-407a-9225afbb000bb85c Today’s Overview Pre-learning: Definitions & tumour characteristics Risk factors In class: Model of carcinogenesis Tumor progression Oncogenes Ras, Myc, Cdks & cyclins Tumour suppressor genes RB, p53, CKIs, APC APC/Beta-catenin review Hallmarks of cancer Warburg effect Limitless replicative potential Carcinogens Assignment - HPV Definitions • Neoplasia = new growth § Aka Tumour § A neoplasm is an abnormal mass of tissue, • Uncoordinated & excessive growth • Continues beyond cessation of growth stimuli § Tumours can be classified as malignant or benign • Benign: remain localized at their site of origin • Malignant: invade and destroy adjacent structures and spread to distant sites Tumour types - nomenclature • “-oma” § often denotes a benign tumour • Eg. Lipoma, osteochondroma, adenoma • Some notable exceptions: lymphoma, melanoma, mesothelioma (all malignant) • “Carcinoma” § Malignant tumour of epithelial cell origin • “Sarcoma” § Malignant tumour of mesodermal/mesenchymal origin – ie muscle, cartilage, bone Tumour types – examples (FYI) Pathologic Basis of Disease(Robbins and Cotran) 10th ed. Table 7.1. Page 270 Tumour characteristics - Differentiation • Differentiation § Extent to which neoplastic parenchymal cells resemble corresponding normal parenchymal cells both morphologically and functionally. • Well differentiated = tumour cells resemble normal cells § Characteristic of benign tumours • Poorly differentiated (aka anaplastic) = tumour cells do not resemble normal cells § Characteristic of malignant tumours Characteristics of Anaplasia • Anaplasia (poorly differentiated ) § Pleomorphism – cells vary in size and shape • May include presence of tumour giant cells § Abnormal nuclear morphology • Nuclei containing abundant chromatic will stain darker than normal (aka hyperchromatic) • Disproportionally large nuclei & nucleoli • Presence of large numbers and abnormal mitoses § Eg. Tripolar or quadripolar § Loss of cell polarity Characteristics of Anaplasia – visuals Pathologic Basis of Disease(Robbins and Cotran) 10th ed. Figure 7.9. Page 272 Pathologic Basis of Disease(Robbins and Cotran) 10th ed. Figure 7.7. Page 271 What features of anaplasia are present? What features of anaplasia are present? Tumour characteristics • In addition to anaplasia, malignant tumours will often show: § Ischemic necrosis – why do you think? § Areas of hemorrhage § Local invasion • Benign tumours are frequently encapsulated and do not demonstrate local invasion • Malignant tumours typically lack a capsule and do extend into adjacent normal tissue Tumour characteristics • In addition to anaplasia, malignant tumours will often show: § Metastasis • Migration to distant tissues via lymphatics or blood vessels • Steps are FYI – for visualization only Pathologic Basis of Disease (Robbins and Cotran) 10th ed. Figure 7.34. Page 306 Tumour characteristics - visual Pathologic Basis of Disease(Robbins and Cotran) 10th ed. Figure 7.16. Page 276 Tumour characteristics Characteristic Differentiation Benign • Well differentiated Malignant • Poorly differentiated (anaplasia) Rate of growth • Progressive & slow • Minimal mitotic figures • Erratic, may be slow to rapid • Numerous and abnormal mitotic figures Local invasion • Well demarcated • No invasion • Locally invasive Metastasis • Absent • Frequent References • Alberts et al. Molecular Biology of the Cell. Garland Science. • Betts et al. Anatomy and Physiology (2ed). OpenStax • Pathologic Basis of Disease(Robbins and Cotran) 10th ed.