Glossary

The following closely related terms may be used to designate abnormal growths:

• Tumor or tumour: originally, it meant any abnormal swelling, lump or mass. In current English, however, the word tumor has become synonymous with neoplasm, specifically solid neoplasm. Note that some neoplasms, such as leukemia, do not form tumors.
• Neoplasm: the scientific term to describe an abnormal proliferation of genetically altered cells. Neoplasms can be benign or malignant:
  • Malignant neoplasm or malignant tumor: synonymous with cancer.
  • Benign neoplasm or benign tumor: a tumor (solid neoplasm) that stops growing by itself, does not invade other tissues and does not form metastases.
• Invasive tumor is another synonym of cancer. The name refers to invasion of surrounding tissues.
• Pre-malignancy, pre-cancer or non-invasive tumor: A neoplasm that is not invasive but has the potential to progress to cancer (become invasive) if left untreated. These lesions are, in order of increasing potential for cancer, atypia, dysplasia and carcinoma in situ.

The following terms can be used to describe a cancer:

• Screening: a test done on healthy people to detect tumors before they become apparent. A mammogram is a screening test.
• Diagnosis: the confirmation of the cancerous nature of a lump. This usually requires a biopsy or removal of the tumor by surgery, followed by examination by a pathologist.