The study aims to:

1. Achieve molecular imaging of EGFR in patients with colorectal neoplasia in vivo using confocal laser endomicroscopy.
2. Compare the results of in vivo EGFR-specific molecular imaging with CLE and ex vivo immunohistochemistry .

Various kinds of tumor markers have been shown to be over-expressed in colorectal cancer, including epidermal growth factor receptor(EGFR). The conventional detection method of EGFR expression in colorectal neoplasia is immunohistochemistry which is time-consuming, and the immunoreactivity can be affected by storage and fixation of tissues. Confocal laser endomicrosopy is a newly developed device which could identify the cellular and subcellular structures clearly with the magnification at×1000, making it possible to explore the physiological and pathological molecular mechanism of the gastrointestinal tract. So the study aims to achieve molecular imaging of EGFR in colorectal neoplasia in vivo using confocal laser endomicroscopy.

Inclusion Criteria：

●Patients known to have large polypoid lesions in colon or rectum from previous examinations from outpatients and inpatients at Qilu Hospital were enrolled into the study

Exclusion Criteria:

• Patients who are allergic to fluorescein sodium
• Patients with impaired cardiac, liver or renal function
• Patients who are unwilling to sign or give the informed consent form
• Patients with giant tumors or obvious GI tract bleeding which make it hard or impossible to observe the lesions
• Patients with coagulopathy
• Patients with pregnancy or breastfeeding

patients known to have large polypoid lesions in colon or rectum from previous examinations from outpatients and inpatients at Qilu Hospital were enrolled into the study