Tumours

Term Paper Title	Tumours
# of Words	601
# of Pages (250 words per page double spaced)	2.4

Tumours

A tumour is a mass of new tissue
growth that does not react to normal controls or
the organizing influence of other tissues, and it has
no useful function in the body. This applies to both
types of tumours, malignant and benign. Malignant,
also known as, cancerous tumours, are
additionally defined by their invasion of local tissue
and their ability to spread to other parts of the
body. Benign Tumours A benign tumour which is
not cancerous, is less serious than malignant
tumours because they do not spread to other parts
of the body, but they may cause damage by local
growth and pressure on other structures,
producing serious complications such as bleeding.
Benign tumours generally grow slowly and kill the
host only if it occupies or attaches to an organ so
as to interfere with a critical function. The cells of
benign tumours closely resemble the cells of the
tissue of origin. Surface benign tumours include
warts and moles. Malignant Tumours A malignant
tumour always kills (unless treated) because of its
invasive and metastatic characteristics. The tumour
grows locally by spreading into surrounding
tissues. Solid tumours, which develop in the
breast, colon, lung, and other organs, contain an
inner core with high pressure zones that compress
and collapse blood vessels, often preventing the
penetration of blood- borne - 2 - cancer
treatments. It spreads to distant sites by the
breaking off of malignant cells, which move
through the blood and lymphatic systems, attach
themselves, and begin to grow as new colonies.
Malignant tumours are diagnosed by examination
of their vascularity, shapes, forms of cells division,
and differentiation. More than a hundred different
types have been identified in humans. In general,
those derived from epithelial tissue are
carcinomas, and those from connective tissue are
sarcomas. The most common form of malignant
tumour of the respiratory tract is lung cancer,
which began increasing in frequency at an alarming
rate about 1940. In 1980 it was the leading cause
of cancer deaths in men and is als...

Click here to view the rest of the document.