Science Fair Project Encyclopedia See the article about cancer
for the main article about malignant tumors. Tumor (American
English) or tumour (British English) originally means
"swelling", and is sometimes still used with that meaning. Tumor
meaning swelling is one of the five classical characteristics of
inflammation. However, the term is now primarily used to denote
abnormal growth of tissue. This growth can be either malignant
or benign. Malignant tumors are called cancer. Cancer has the
potential to invade and destroy neighboring tissues and create
metastases. Benign tumors do not invade neighboring tissues and
do not seed metastases, but may locally grow to great size. They
usually do not return after surgical removal. Depending on
tissue of origin, tumors may be: - Tumors of epithelial origin.
- squamous epithelium: squamous cell papilloma , squamous cell
carcinoma - transitional epithelium: transitional cell papilloma
, transitional cell carcinoma - basal cell (only in skin): basal
cell carcinoma - gl