All About Neoplasia : From Beginners to Pro in diagnosis : Part 4/4 скачать в хорошем качестве

All About Neoplasia : From Beginners to Pro in diagnosis : Part 4/4

All About Neoplasia : From Beginners to Pro in diagnosis : Part 4/4 Neoplasia lecture series : All lectures link : Neoplasia Part 1:    • All About Neoplasia : From Beginners to Pr...   Neoplasia Part 2:    • All About Neoplasia : From Beginners to Pr...   Neoplasia Part 3:    • All About Neoplasia : From Beginners to Pr...   Neoplasia Part 4:    • All About Neoplasia : From Beginners to Pr...   The term neoplasm refers to the tumour mass itself. The process that occurs to produce a neoplasm is called neoplasia. Willis defined a neoplasm as “an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the surrounding normal tissues, and persists in the same excessive manner after cessation of the stimuli which evoked the change”. (For example, once a lung cancer has developed, it doesn’t go away if the individual stops smoking.). Neoplasms have an increase in cell numbers that must be distinguished from the reversible increase in cell number (hyperplasia such as in enlarged prostates of older men) or cell size (hypertrophy such as in the enlarged uterus of pregnancy) that may also be seen in larger organs. Essential features of neoplasia or tumour growth include: Tumours are composed of living cells, which differ from the cells of the normal organ from which the tumour is derived in that the cell division, cell death and cell differentiation controls operating in that tissue or organ have been deregulated or lost The control of cell division, death and differentiation may have been lost to the extent that the tumour: (a) loses partially or totally specialised functions (cell appearance changes) (b) acquires new functions such as invasion – the capacity to infiltrate the surrounding tissues and organs and metastasis – the ability to spread to and proliferate in distant parts of the body after tumour cells have been transported by lymph or blood or along body spaces Definitions - benign and malignantPart 2 of 11 Neoplasms are divided into benign and malignant. Benign neoplasms do not invade or metastasise (spread), whereas malignant neoplasms show evidence of invasion (or infiltration) into adjacent tissues, often in a destructive way and many will undergo metastasis (spread to other sites in the body to form secondary tumours – the original is often called a primary tumour). Benign tumours Benign tumours are those which proliferate and divide but do not invade the surrounding tissues, nor metastasize. Such benign neoplasms or tumours and the use of the term benign implies that their growth is not life-threatening, and their clinical course is predictable. They may cause problems due to pressure, obstruction or excessive hormone production. Malignant neoplasms Neoplasms which invade and/or metastasise are malignant neoplasms (often called cancers in ordinary language). Their clinical course is progressive; unless adequate therapy is available the patient will eventually die as a result of the disease. Cancers show destructive invasive growth behaviour and can produce signs and symptoms such as: Blood loss – ulceration and haemorrhage Pressure and destruction of adjacent tissue Obstruction or constriction of flow in vital organs Metabolic effects: general – cachexia (severe weight loss including a reduction in muscle mass); and specific – production/secretion of tumour-specific products/hormones #neoplasia,#neoplasiapathology,#neoplasiapathologylecture,#neoplasiapathologyunacademy,#neoplasiapathologybrainlessmedicos,#neoplasiapathologydrnajeeb,#neoplasiapathologyrobbins,#neoplasiapathologyninjanerd,#neoplasiailovepathology,#neoplasianinjanerd,#neoplasiadrnajeeb,#neoplasianomenclature,#neoplasiapathophysiology,#neoplasiaosmosis,#neoplasiapathologylecturebangla,#neoplasiaand,#neoplasiaandcarcinogenesis,#neoplasiaanddysplasia