An introduction to malignancy..from the brain of a MS

Malignancy,neoplasm--> a group of cells with unlimited growth potential and whose growth is uncoordinated with that of normal cells,normally unresponsive to growth inhibitors or excessively responsive to growth factors.

cancer- "crab" due to the uncoordinated growth pattern of malignant tumor resembling the way crabs walk

TUMOR-->a group of cells which grow excessively creating a mass,not necessarily malignant

There are at least7 difference between a benign and malignant tumor

malignant- margins are poorly demarcated,irregular infiltrative growth pattern,usually red and hemorrhagic(angry looking),surface are irregular,able to metastasis,ulceration,capable of invasion

HALLMARKs of neoplasm: GRAAAM
G-self sufficient in GROWTH SIGNAL
R-unlimited REPLICATIVE POTENTIAL
A-abnormal APOPTOSIS(programmed cell death)
A-unresponsive to ANTIGROWTH signal
A-excessive ANGIOGENESIS(blood vessel formation)
M-capable of METASTASIS(spread from 1 organ to the others)

Causes of neoplasm: Physical agent-Radiation,UV light
Chemical agent-nitrites,oxidising agent e.g. Hydrogen peroxide,
Biological agent-virus e.g. HPV type 16 and 18(cervical adenocarcinoma),bacteria e.g. H.pylori(gastric carcinoma),parasite e.g. Schistosoma.haematobium(Urothelioma)

Terminologies:
carcinoma-neoplasm of epithelial tissue
sarcoma-neoplasm of connective tissue
adenocarcinoma-carcinoma with glandular pattern of cell arrangement
squamus cell carcinoma-carcinoma with squamus(layered) pattern of cell arrangement

benign tumor is recognised by adding -oma to the word,e.g. lipoma(benign growth of the fat tissue),angioma(benign growth of vessels)
However there are exceptions-->e.g.lymphoma(malignant growth of the lymphoid cells),astrocytoma(malignant growth of astrocytes),ependymoma(malignant growth of ependymal cells)

some special names--> leukemia(cancer of white blood cells),carcinomatosis peritonei(advanced stage of cancer involving the whole peritoneum),carcinomatosis cerebri(involving whole cranium),pseudomyxoma peritonei(excessive accumulation of mucin in peritoneum now thought to most likely originate from a appendicical tumor),struma ovarii(presence of foreign tissue e.g. thyroid in the ovary)

in the next post, the neoplasm that i am most familiar with will be discussed. Although this tumor is very very very rare, it happens,to my mum. The one cancer which killed her: Duodenojejunal adenocarcinoma leading to carcinomatosis peritonei. stay tune!