Spread of cancer cells from the primary site, and the formation of new tumors at secondary sites.
This refers to tumour that has spread to other parts of the body. These metastases ( distant tumour deposits) can either be very small ( micro in size or micrometastases) or large and easily detectable ( macro-metastases or detectable metastases).
Microscopic spread of tumor cells, not yet detectable.
Small area of cancer cell spread that are too small to be detected without a microscope.