Surgery How in Situ Is Used During Surgery and Cancer Treatment By Jennifer Whitlock, RN, MSN, FN Jennifer Whitlock, RN, MSN, FN LinkedIn Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine. Learn about our editorial process Updated on November 01, 2021 Medically reviewed by Doru Paul, MD Medically reviewed by Doru Paul, MD Doru Paul, MD, is board-certified in internal medicine, medical oncology, and hematology. Learn about our Medical Expert Board Fact checked by Nick Blackmer Fact checked by Nick Blackmer LinkedIn Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years’ experience in consumer-oriented health and wellness content. Learn about our editorial process Print In situ is Latin for "in place" or "in position." In medicine, it may also mean "localized." The term is used in both surgery cases and cancer diagnosis and treatment. Morsa Images / Getty Images Surgery The term in situ typically refers to seeing the structures of the body where they belong. For surgeons, this means visualizing the tissue in question in the human body, where it normally rests, by creating an incision to allow the tissue to be visually examined. Surgery is the best way to visualize tissues of the human body in situ, as imaging studies such as CT scans and MRI scans can show the locations of organs but does not allow direct viewing of the tissue. Cancer For cancer diagnosis and treatment, in situ has a very specific meaning. When cancer is diagnosed it may be referred to as cancer "in situ." This means that cancer has remained in the place where it started. This is an important distinction between the site of origin and sites where cancer may have spread. In situ is a pathologic diagnosis made with a microscope. For the patient, cancer in situ is a good thing. This indicates that cancer has not spread, or metastasized. This type of cancer may be referred to as Stage 0. When cancer metastasizes, it invades other nearby tissues and organs or spreads throughout the body. It is far better to have one site than multiple sites, as treatment is more likely to be successful. Pronunciation: in-sigh-too Common Misspellings: insitu, insite, in site, insitu cancer, insightu, Examples: The surgeon wanted to see the kidney in situ, before making a final diagnosis. By Jennifer Whitlock, RN, MSN, FN Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit