Neoplasia - Neoplasia *rim of normal tissue is removed...

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Neoplasia **rim of normal tissue is removed around tumour too=resection margin 2 outcomes of cell injury: cell dies or alive→ goes on to adapt via: Cellular Adaptation to Stress: 1. Atrophy: decreased in size and function of cell Causes: decreased workload, decreased blood supply, loss of innervations, interruption of trophic signal, aging If atrophy persists the cells may die Ex. Atrophy of thyroid following pituitary resection; atrophy of brain in aging (Alzheimer’s) 2. Hypertrophy: increase in the size of a cell accompanied by an augmented functional capacity Causes: increased function demand (myocardial hypertrophy in hypertension—muscles cannot proliferate but can increase in size; muscle hypertrophy in athletes), physiological (hormonal) hypertrophy (sex organs at puberty) 3. Hyperplasia: increase in the number of cells in an organ or tissue Causes: increased functional demand (increased RBCs in high altitude—decreased O2 levels so adapt by increasing RBC production), hormonal stimulation (endometrium in early phase of menstrual cycle), persistent cell injury (skin in calluses)—all above are PHYSIOLOGIC All are reversible via removing stimulus 4. Metaplasia: conversion of one differentiated cell type to another Ex conversion of bronchial ciliated columnar epithelium to squamous epithelium in smokers Although it’s a protective mechanism, there may be loss of function Differentiated=normal Not cancer Normal cell→ DIFFERENT normal cell 5. Dysplasia: alteration in size, shape and organization of the cellular components of a tissue Features: Variation in shape and size of cells (cellular pleomorphism) Variation in nuclear shape and size (nuclear pleomorphism) Enlargement, irregularity and hyperchromatism of the nuclei Disordered arrangement of the cell Significance: dysplasia is a pre-malignant (ie. No invasion is present) lesion Persistent injury may lead to dysplasia; ex. Dysplasia in bronchial epithelium, dysplasia in cervical epithelium “dysplastic tissue”= big and small nuclear sizes and cell sizes; disorganized; different cells and different sizes What you look for in a PAP smear Standard in epithelial malignancies Catch them at dysplastic state= can get 100% cure rate Epidemiology 84800 Canadian women, and 93000 Canadian men will be diagnosed with cancer 35100 women and 39900 men will die of cancer 3487 Canadians will be diagnosed with cancer every day; 205 Canadians will die of cancer every day Canada: 40% of women and 45% of men will develop some form of cancer and ¼ will die of it Next to heart disease= most common cause of death Leading cause of premature death in Canada; 1 million potential years of life lost in Canada Glossary: Neoplasia= new growth= tumour Oncology (oncos=tumour)= study of tumours Cancer=malignant neoplasm Malignant tumour= tumour that invades and spreads to distant sites
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Neoplasia - Neoplasia *rim of normal tissue is removed...

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